WASHINGTON, United States — US Secretary of State Antony Blinken on Wednesday brushed off Chinas diplomacy with Russia as a "marriage of convenience," and said Beijing had not yet provided military aid to "junior partner" Moscow to fight in Ukraine.

President Xi Jinping on Wednesday closed a trip to Moscow that was closely watched in Washington, which considers China the greatest long-term adversary of the United States -- and which is also supporting Ukraine in its fight against Russian invaders.

"In part as a result of having this very different worldview than we do, they have a marriage of convenience. Im not sure if its conviction," Americas top diplomat told the Senate Foreign Relations Committee.

"Russia is very much the junior partner in this relationship," he said.

Blinken said that while China was pushing an "illiberal" vision to replace the US-led world order, "Im not sure Russia or Putin actually wants a world order -- maybe more like world disorder."

Blinken has publicly warned for weeks that China is considering Russian requests for weapons to fight in Ukraine, with some reports indicating limited shipments by Chinese companies to Moscow.

"As we speak today, we have not seen them cross that line," Blinken said in response to a question on whether China was providing "lethal aid" to Russia.

Russia, one of the worlds top military powers, has been obliged to rely on Iran and North Korea for supplies as it suffers losses in Ukraine, according to US intelligence.

Xi in Moscow promoted a Chinese proposal for a ceasefire in Ukraine -- a call met with skepticism by the United States, which fears Russia would use a pause to regroup battered forces on the ground.

"I think their diplomatic support, their political support, and to some extent material support for Russia certainly goes against our interest in bringing this war to an end," Blinken said of China.