Berlin, Oct 3 (AP/UNB) — Germany on Wednesday celebrated the 28th anniversary of the reunification of east and west, a process that Chancellor Angela Merkel said still isn't complete. The country's leaders voiced concern about divisions in society and the rise of populism.

Germany was reunited on Oct. 3, 1990, following more than four decades of Cold War division, and less than a year after communist East Germany opened its heavily fortified border.

While much progress has been made since then, economic and other differences between the west and the less prosperous east still persist. German leaders' remarks at a ceremony marking Wednesday's anniversary reflected concern about new divisions and polarization in German society — by no means all along east-west lines.

Merkel, who grew up in East Germany, said that "German unity is not complete" and still poses challenges today.

"Twenty-eight years later, we know that what we call German unity is a process, a long road, that calls on us again and again to listen to each other," she said.

Over the past three years, the arrival of large numbers of refugees and other migrants has fed increasing political polarization in Germany. The nationalist Alternative for Germany party, which has support across the country but is particularly strong in the east, entered the national parliament last year.

Violent right-wing protests a month ago following the killing of a German man, allegedly by migrants, in the eastern city of Chemnitz, have added to concerns.

"We won't let ourselves be divided, and that is not a question of east and west — it is not that simple," Berlin Mayor Michael Mueller told the main reunification ceremony at the capital's Staatsoper opera house.

"We in Germany also are seeing the populist presumption of positioning the 'people' against political opponents, against supposed and actual minorities, against those elected by the people," said parliament speaker Wolfgang Schaeuble, who helped negotiate German reunification. "But no one has the right to say that he alone represents the people."

He advocated a "contemporary patriotism" marked by "self-confidence, calm and optimism."

Paris, Oct 3 (AP/UNB) — French Prime Minister Edouard Philippe has assumed responsibility for France's domestic security after the interior minister resigned in an apparent act of defiance toward President Emmanuel Macron.

In a cold handover ceremony Wednesday, Philippe said his main focus would be to ensure "the highest security level" in the country.

Philippe is in charge until Gerard Collomb's successor is appointed.

Macron accepted Collomb's resignation late Tuesday, after initially refusing it the previous day. Collomb insisted he wanted to leave to be able to run for mayor of the city of Lyon in 2020.

Collomb, 71, was one of Macron's closest political allies. His decision comes amid a string of bad news events for the French president, who has reached record low popularity in polls since his election in May 2017.

Birmingham, Oct 3 (AP/UNB) — Prime Minister Theresa May will urge her fractured Conservative Party to unite behind "decent, moderate and patriotic" policies, a day after her rival Boris Johnson challenged her authority with a crowd-pleasing speech of his own.

May is ending the party's annual conference Wednesday with a call for the party to show that it "delivers on the issues (voters) care about and is comfortable with modern Britain in all its diversity."

The four-day conference has been dominated by divisions over Brexit, with pro- and anti-EU camps both criticizing the prime minister's negotiations with the EU.

Johnson drew cheers from 1,500 delegates on Tuesday when he called May's plan an "outrage."

May acknowledged that Johnson's speech had made her "cross" but said she was sticking to her Brexit blueprint.

Brussels, Oct 3 (AP/UNB) — The U.S. envoy to NATO on Tuesday said that Russia must halt development of new missiles that could carry nuclear warheads and warned that the United States would be looking at its capability to "take out" the system if it becomes operational.

NATO fears the 9M729 system contravenes the 1987 Intermediate-range Nuclear Forces Treaty, or INF. The Cold War-era pact bans an entire class of weapons — all land-based cruise missiles with a range between 500-5,500 kilometers (310-3,410 miles), and the alliance says that the Russian system fits into that category.

"It is time now for Russia to come to the table and stop the violations," U.S. Ambassador Kay Bailey Hutchison told reporters in Brussels, on the eve of a meeting between U.S. Defense Secretary Jim Mattis and his NATO counterparts.

She said that if the system "became capable of delivering," the U.S. "would then be looking at the capability to take out a missile that could hit any of our countries in Europe and hit America."

Hutchinson later clarified her position in a tweet in which she said she was not talking about preemptively striking Russia. Rather, she said in the tweet that her point was: Russia "needs to return to INF Treaty compliance or we will need to match its capabilities to protect US & NATO interests."

Washington has shared intelligence evidence with its 28 NATO allies that Russia is developing the ground-fired cruise missile and that the system could give Moscow the ability to launch a nuclear strike in Europe with little or no notice.

Russia has claimed that U.S. missile defenses violate the pact. In the past, the Obama administration worked to convince Moscow to respect the INF treaty but seemed to make no progress.

Mattis said Tuesday that he intends to bring the issue up during the NATO meeting. After four years of diplomatic effort, he said, the U.S. is living by the treaty and Russia is not. He said there is a lot of concern about that at the U.S. State Department and on Capitol Hill.

"I'm going to lay out the situation," Mattis said during a news conference in Paris. "I want their advice as I return to Washington, D.C."

Hutchison said the U.S. doesn't want to violate the treaty but that Russia could force its hand.

"There will come a point in the future in which America will determine that it has to move forward with a development phase that is not allowed by the treaty right now," she said.

Washington wants its NATO allies to ramp up diplomatic pressure on Moscow, and NATO Secretary-General Jens Stoltenberg said that all allies are concerned by Russia's continued work on the system.

"Russia has not provided any credible answers on this new missile," said Stoltenberg, adding that the INF is a "crucial element" of trans-Atlantic security which is now "in danger because of Russia's actions."

Stockholm, Oct 2 (AP/UNB) — Three scientists from the United States, Canada and France won the Nobel Prize in physics Tuesday for work with lasers described as revolutionary and bringing science fiction into reality.

The American, Arthur Ashkin, entered the record books of the Nobel Prizes by becoming the oldest laureate at age 96. Donna Strickland, of the University of Waterloo in Canada, became the first woman to win a Nobel in three years and is only the third to have won the prize for physics.

Frenchman Gerard Mourou of the Ecole Polytechnique and University of Michigan will share half of the 9 million kronor ($1.01 million) the prize carries with Strickland; Ashkin gets the other half.

Sweden's Royal Academy of Sciences, which chose the winners, said Ashkin's development of "optical tweezers" that can grab tiny particles such as viruses without damaging them realized "an old dream of science fiction — using the radiation pressure of light to move physical objects."

The tweezers are "extremely important for measuring small forces on individual molecules, small objects, and this has been very interesting in biology, to understand how things like muscle tissue work, what are the molecule motors behind the muscle tissue," said David Haviland of the academy's Nobel committee.

Strickland and Mourou helped develop short and intense laser pulses that have broad industrial and medical applications, including laser eye surgery and highly precise machine cutting. The academy said their 1985 article on the technique was "revolutionary."

"With the technique we have developed, laser power has been increased about a million times, maybe even a billion," Mourou said in a video statement released by Ecole Polytechnique.

Strickland's award was the first Nobel Prize in physics to go to a woman since 1963, when it was won by Maria Goeppert-Mayer; the only other woman to win for physics was Marie Curie in 1903.

"Obviously, we need to celebrate women physicists because we're out there. And hopefully in time, it'll start to move forward at a faster rate, maybe," Strickland said in a phone call with the academy after the prize announcement.

On winning the Nobel, Strickland told The Associated Press: "I just find the whole thing surreal."

"I mean, I sort of went to the university thinking 'Oh, I just want to do the world's best Ph.D,'" she said. "And in the end I got to do that. And now, obviously, even the whole world agrees with me that I got to do that."

Michael Moloney, CEO of the American Institute of Physics, praised all the laureates.

"It is also a personal delight to see Dr. Strickland break the 55-year hiatus since a woman has been awarded a Nobel Prize in physics, making this year's award all the more historic," Moloney said.

He credited the work of all three with "expanding what is possible at the extremes of time, space and forms of matter."

Ashkin's tweezers can be used to hold and manipulate proteins, DNA and other biomolecules to study their mechanical properties or stimulate them, said Erwin Peterman, a physicist at Vrije Universiteit Amsterdam, who called the award "a great recognition for this visionary scientist who was ahead of his time."

Ashkin could not immediately be reached for comment. The Swedish academy identified him as affiliated with Bell Labs in Holmdel, New Jersey. Previous news reports on his work said he retired in 1992 from the giant research complex, which later was spun off by Bell and mostly closed.

On Monday, American James Allison and Japan's Tasuku Honjo won the Nobel medicine prize for groundbreaking work in fighting cancer with the body's own immune system.

The winner or winners of the Nobel chemistry prize will be announced Wednesday, followed by the peace prize on Friday. The economics prize, which is not technically a Nobel, will be announced Oct. 8.