The Kremlin warned Wednesday that increasing the supply of U.S. arms to Ukraine would aggravate the devastating 10-month war ignited by Russia’s invasion, and Russia’s defense minister called for expanding Moscow’s military by at least 500,000 troops.

Speaking during a meeting with his top military brass, Russian President Vladimir Putin said Moscow would use lessons learned in the conflict to “develop our armed forces and strengthen the capability of our troops.” He said special emphasis would go to developing nuclear forces, which he described as “the main guarantee of Russia’s sovereignty.”

Putin also said the Russian military’s new Sarmat intercontinental ballistic missile would enter service shortly. The Sarmat is intended to replace aging Soviet-built ballistic missiles and form the core of Russia’s nuclear forces. Putin has hailed its capacity to dodge missile defenses.

The bullish rhetoric from Moscow came as Ukrainian President Volodymyr Zelenskyy met with President Joe Biden in Washington, where U.S. officials announced a huge new military aid package for Kyiv. The $1.8 billion package includes for the first time a Patriot missile battery and precision guided bombs for fighter jets, U.S. officials said.

Defense Minister Sergei Shoigu said the beefed-up Russian military will include 695,000 volunteer contract soldiers, 521,000 of whom would be recruited by the end of 2023. The Russian military had about 400,000 contract soldiers as part of its 1 million-member military before the fighting in Ukraine began.

All Russian men ages 18 to 27 are obliged to serve in the military for one year, but many use college deferments and health exemptions to avoid the draft. Shoigu said the draft age range would be changed to 21- to 30-years-old, and the recruits would be offered a choice of serving for one year as draftees or signing a contract with the military as volunteers.

He also said Russia would form new units in the country’s west in view of ambitions by Finland and Sweden to join NATO.

The Kremlin’s plans marked a return to the Soviet-era military structure, which Russia abandoned during recent reforms that saw the creation of smaller units. Some Russian military experts have argued the more compact units intended for use in local conflicts were undermanned and underequipped for a massive conflict like the action in Ukraine.

Kremlin spokesman Dmitry Peskov said the expansion of Western weapon supplies to Ukraine has led to “an aggravation of the conflict and, in fact, does not bode well for Ukraine.”

Peskov’s comments were the first official Russian reaction to news that Zelenskyy was in Washington for his first known foreign trip since Russia’s Feb. 24 invasion triggered the war that has killed thousands and laid waste to towns and cities across Ukraine.

The announcement of the new U.S. military aid came just hours before Zelenskyy paid a visit to the White House to thank U.S. leaders and “ordinary Americans” for their support in fighting off the invaders and to press for continued aid.

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Biden said the U.S. and Ukraine would continue to project a “united defense” as Russia wages a “brutal assault on Ukraine’s right to exist as a nation.”

Later, in a historic address to Congress aimed at sustaining U.S. and allied aid for Ukraine’s defense, Zelenskyy thanked “every American” for their support of his country.

Zelenskyy called U.S. support vital to Ukraine’s efforts to beat back Russia, and thanked lawmakers and everyday citizens for tens of billions of dollars in military and economic assistance over the last year.

The Ukrainian leader predicted that next year would be a “turning point” in the conflict, “when Ukrainian courage and American resolve must guarantee the future of our common freedom — the freedom of people who stand for their values.”

Moscow also was involved in high-level diplomacy. The deputy head of Russia’s Security Council, Dmitry Medvedev, met Wednesday with Chinese President Xi Jinping. Medvedev, a former Russian president, said in a video statement that he and Xi discussed an array of topics, including “the conflict in Ukraine.” Medvedev did not elaborate.

China has refused to condemn Russia’s invasion of Ukraine and criticized sanctions against Moscow. Beijing has only referred to the invasion as the “Ukraine situation” in deference to Moscow, and accused the U.S. and NATO of provoking Putin by expanding into eastern Europe.

In other developments Wednesday, Dmitry Rogozin, the former Russian deputy prime minister and one-time head of the state space agency Roscosmos, was wounded during Ukrainian shelling of a hotel in the Russian-controlled city of Donetsk.

Rogozin, who joined the Russian troops in Ukraine as a volunteer, told Russian state-controlled RT that a shell fragment missed his spine by just a centimeter (0.4 inches). Russian news agencies quoted Rogozin’s aide as saying that he was hospitalized, but his life wasn’t in danger.

Russian messaging app channels said Rogozin was celebrating his birthday at a restaurant when it was hit. Several other people, including the Moscow-appointed head of the regional government in Donetsk, were also wounded.

Russia annexed the Donetsk region along with three other regions of Ukraine in September.

Elsewhere, Russian forces pounded populated areas with more missiles and artillery. They shelled areas around the city of Nikopol in Ukraine’s southeastern Dnipropetrovsk region, its governor, Valentyn Reznichenko, said Wednesday on Telegram.

Nikopol is across the Dnieper River from the Zaporizhzhia Nuclear Power Plant. Russian forces currently occupy the plant, Europe’s largest nuclear power station.

The Ukrainian president’s office reported Wednesday that Russian attacks on Tuesday killed five civilians and wounded 17. The General Staff of the Armed Forces of Ukraine said Russia unleashed five missiles and 16 airstrikes on Ukrainian territory and 61 attacks from multiple-launch rocket systems.

General Staff spokesperson Oleksandr Shtupun said Ukrainian forces repelled attacks around more than 25 populated areas in eastern Ukraine’s Kharkiv, Donetsk and Luhansk provinces, with the cities of Bakhmut and Avdiivka continuing to be key targets of Russia’s grinding offensive.

The bodies of seven civilians, including a teenage girl, were found in a mass grave in the village of Pravdyne in southern Ukraine’s Kherson province, the Ukrainian defense minister said Wednesday. The village was held by Russian forces from March until early November.

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“They simply kill,” Oleksii Reznikov wrote on Twitter. He said that as, of Dec. 21, the bodies of about 500 civilians who died during the Russian occupation have been found in the country’s northeastern Kharkiv province.