With East-West tensions at their highest point since the collapse of the Soviet Union in the 1990s, U.N. Secretary-General Antonio Guterres said Friday the world is probably a more dangerous place now than during the Cold War.

Guterres warned that a small mistake or miscommunication between major powers could have catastrophic consequences.

Read: Allies watch for Kremlin attempt to justify Ukraine invasion

“I am often asked whether we are in a new Cold War,” Guterres said in his opening speech at an annual security conference in Munich. “My answer is that the threat to global security now is more complex and probably higher than at that time.”

During the decades-long standoff between the Soviet Union and the United States in the 20th century, “there were mechanisms that enabled the protagonists to calculate risks and use back-channels to prevent crises,” Guterres said. “Today, many of those systems no longer exist and most of the people trained to use them are no longer here with us.”

But he said he still believes the buildup of Russian troops around Ukraine won’t result in a military conflict.

“I urge all parties to be extremely careful with their rhetoric. Public statements should aim to reduce tensions, not inflame them,” Guterres said.

Read: NATO: Russia misleads world on troop movements near Ukraine

While U.S. Vice President Kamala Harris, Secretary of State Anthony Blinken, and Ukrainian President Volodymyr Zelenskyy were attending the Munich Security Conference, there was no senior official present from Russia.

German Foreign Minister Annalena Baerbock said the Russians missed an opportunity.

“Particularly in the current, extremely threatening situation it would have been important to also meet Russian representatives in Munich,” she said in a statement ahead of the conference. Even tiny steps toward peace would be “better than a big step toward war.”