Russia accused the United States on Saturday of "playing with fire" around Taiwan while China said it will press on working for "peaceful reunification" with the democratically governed island and pledged to take forceful steps to oppose any external interference, a thinly-veiled reference to Washington.

Tensions over Taiwan between Washington and Beijing have soared after a visit there in August by House Speaker Nancy Pelosi, which was followed by large-scale Chinese military drills as well as a pledge by President Joe Biden to defend the Chinese-claimed island.

Weeks before Russian President Vladimir Putin launched an invasion of Ukraine in February, he and his Chinese counterpart Xi Jinping declared a "no limits" partnership, inking a promise to collaborate more against the West.

Putin's top diplomat Sergei Lavrov in his Saturday address to the United Nations General Assembly targeted Washington's Taiwan stance as well as the Western sanctions on Moscow over the war in Ukraine.

"They're playing with fire around Taiwan. On top of that, they're promising military support to Taiwan," Lavrov said.

Putin explicitly backs China over Taiwan. "We intend to firmly adhere to the principle of 'One China'," Putin said last week. "We condemn provocations by the United States and their satellites in the Taiwan Strait."

Asked last week in a CBS 60 Minutes interview whether U.S. forces would defend Taiwan, Biden replied: "Yes, if in fact, there was an unprecedented attack."

The statement was his most explicit to date about committing U.S. troops to the defend the island. It also appeared to go beyond a long-standing U.S. policy of "strategic ambiguity," which does not make clear whether the United States would respond militarily to an attack on Taiwan.

Speaking moments before Lavrov, Chinese Foreign Minister Wang Yi said Beijing would continue to work for "peaceful reunification" with Taiwan, and it would combat "separatist activities" towards Taiwan independence while taking forceful steps to oppose any external interference.

"Only by resolutely forestalling separatist activities can we forge a true foundation for peaceful reunification. Only when China is completely reunified, can there be enduring peace across the Taiwan Strait," he said.

His comments come a day after a 90 minute-long meeting with U.S. Secretary of State Antony Blinken in New York, their first talks since Pelosi's visit to Taiwan in August.

After the meeting, China accused the United States of sending "very wrong, dangerous signals" on Taiwan. Blinken told Wang maintenance of the peace and stability of Taiwan was vitally important, a senior Biden administration official told reporters.

China sees Taiwan as one of its provinces. Beijing has long-vowed to bring Taiwan under its control and has not ruled out the use of force to do so.

Taiwan's democratically-elected government strongly objects to China's sovereignty claims and says only the island's 23 million people can decide its future.

China's Ukraine Warning

Wang said China supported all efforts conducive to the peaceful resolution of the "crisis" in Ukraine, but cautioned against a potential spillover of the war.

"The fundamental solution is to address the legitimate security concerns of all parties and build a balanced, effective and sustainable security architecture," Wang said in his address.

"We call on all parties concerned to keep the crisis from spilling over and protect the legitimate rights and the interests of developing countries."

China has criticized Western sanctions against Russia but stopped short of endorsing or assisting in the military campaign.

Russian President Vladimir Putin last week said China's leader Xi Jinping had concerns about Ukraine.