The United States on Wednesday expressed concern over China's alignment with Russia after the leaders of the two countries reaffirmed their partnership in phone talks in the midst of Moscow's invasion of Ukraine.

A U.S. State Department spokesperson said that in the call, President Xi Jinping "made clear he stands by" his statement to Russian President Vladimir Putin ahead of the invasion in February that Beijing's friendship with Moscow has "no limits."

During the call, Xi and Putin agreed to work together to counter the international order dominated by the United States and democratic European nations, according to the Chinese Foreign Ministry.

Amid Russia's prolonged military campaign against Ukraine, Xi was also quoted by the ministry as telling Putin that Beijing is willing to continue supporting Moscow so that Russia can safeguard its core interests, such as sovereignty and security.

"More than three months into Russia' brutal invasion, China is still standing by Russia," the spokesperson said.

"It is still echoing Russian propaganda around the world. It is still shielding Russia in international organizations...and it is still denying Russia's atrocities in Ukraine by suggesting instead that they were staged," the official said.

Since Russia launched a major attack on Ukraine on Feb. 24, China has shied away from criticizing Moscow while opposing punitive sanctions on the nation imposed by the United States and European countries.

As another sign of their eagerness to develop bilateral ties, the State Department official touched on joint military China-Russia exercises, including a recent strategic bomber patrol in East Asia.

Late last month, six Chinese and Russian strategic bombers, including suspected ones, made a long-distance flight over the Sea of Japan, the East China Sea and the Pacific.

"Nations that side with Vladimir Putin will inevitably find themselves on the wrong side of history," the spokesperson said.