The ship's presence at the Chinese port underscores the challenges facing the United States and its allies as they try to choke off military and economic support for Russia.

China is providing moorage for a U.S.-sanctioned Russian cargo ship implicated in North Korean arms transfers to Russia, according to satellite images obtained, as U.S. concerns grow over Beijing's support for Moscow's war in Ukraine.

Britain's Royal United Services Institute (RUSI) think tank said the Russian vessel Angara, which since August 2023 has moved to Russian ports thousands of containers believed to contain North Korean munitions, has been anchored at a Chinese shipyard in eastern Zhejiang province since February.

The ship's presence at the Chinese port underscores the challenges facing the United States and its allies as they try to choke off military and economic support for Russia.

With Ukraine under a renewed Russian assault and running short of ammunition, U.S. officials have issued increasingly stark warnings about what they say is China's help rebuilding Russia's military after its early setbacks in the Ukraine war.

That support is expected to top the agenda this week as Secretary of State Antony Blinken visits Beijing.

The State Department's second ranked diplomat, Kurt Campbell, said this month that Washington would not "sit by" if Beijing increased its backing for Moscow.

A spokesperson for the U.S. State Department said it was aware of "credible, open-source reports" that the Angara is currently moored in a Chinese port and had raised the issue with Chinese authorities.

Satellite images RUSI obtained in recent months from companies including San Francisco-based Earth imaging firm Planet Labs PBC showed the Angara docked at Zhoushan Xinya Shipyard in Zhejiang, which on its website says it is China's largest private ship repair company.

The ship was identified by its unique automatic identification system (AIS) transponder that had been briefly turned on, likely for safety reasons, while navigating a busy stretch of the Korea Strait en route to China.