The United States hopes Beijing will not use a visit by US lawmakers to Taiwan as a pretext for military action, a senior US diplomat said on Wednesday, adding that all countries should warn China against conflict on the island, Reuters reported.

Relations between the United States and China were rocked last August by the visit of then-Speaker of the US House of Representatives Nancy Pelosi to democratic Taiwan, which Beijing claims as its territory.

Since then, several American politicians have visited Taiwan, and there has been speculation that Republican Rep. Kevin McCarthy, who took over as speaker of the House of Representatives in January, may visit the island soon, possibly in the spring or summer.

US Assistant Secretary of State Wendy Sherman said the United States is committed to supporting Taiwan and its ability to defend itself as a result of the “one China” policy.

“And we hope that the PRC (People’s Republic of China) will not use the visit of a member of Congress to Taiwan as a pretext for military action,” Sherman said.

After Pelosi’s visit, China stepped up military exercises around Taiwan. Tense relations between Washington and Beijing further worsened this month after the US military shot down what it said was a Chinese reconnaissance balloon that flew over US territory.

Sherman, the State Department’s second-ranking diplomat, cited Russia’s invasion of Ukraine as a lesson for China against any moves in the Taiwan Strait, saying the war has increased energy and food security for the world, as well as inflationary pressures.

“The same would be true of a conflict in the Taiwan Strait,” Sherman said. “And that’s why I call on all countries to tell China that this concerns them. It concerns my people, my country. It’s not a good idea,” she said.

Sherman said Washington is “increasingly concerned” about China’s “unstoppable” partnership with Russia and its support for Moscow’s invasion of Ukraine, even as it seeks to bolster its global standing by saying it will help mediate an end to the conflict. She said China cannot have it both ways.

Sherman says the Ukrainians will deal a strategic setback to Russian President Vladimir Putin, and “that will create a lot of problems for those who support this invasion in the future.”