The United States has not seen China sending actual weapons to Russia for use in Ukraine though North Korea and Iran have engaged in arms transactions with Moscow, Secretary of State Antony Blinken said during a Senate committee hearing Tuesday.

Blinken made the distinction, while reiterating concerns over China's "overwhelming" support for Russia's defense industrial base. He vowed to continue to sanction entities engaged in the transfers to Russia of "dual-use" items that can be diverted for military purposes.

"We have not seen China provide actual weapons to Russia for use in Ukraine. North Korea is doing that. Iran is doing that," he said during the hearing of the Senate Foreign Relations Committee on the State Department's budget request for the fiscal year 2025.

"What we are seeing is China providing overwhelming support to Russia's defense industrial base," he added.

The secretary noted that Russia has brought in large amounts of machine tools, microelectronics and other imports from China amid its protracted war in Ukraine.

"A lot of that goes to building up the defense industrial base," he said. "We've seen -- as a result -- Russia churning out tanks, artillery ammunition at a record pace."

Blinken raised this issue directly with Chinese President Xi Jinping and his counterpart, Wang Yi, during a trip to Beijing last month, he said.

"We've called it out publicly. We've brought the information to allies and partners. And it's very clear ... particularly for the Europeans who see in Russia's aggression against Ukraine a larger threat to their own security," he said.

"You can't have China on the one hand professing to seek better relations with countries in Europe, while on the other hand, fueling the greatest security threat to Europe since the end of the Cold War."

He noted that Washington has sanctioned more than 100 Chinese entities that were engaged in providing dual-use items and others to Russia.

"We will continue to do that," he said.

The Senate hearing was interrupted several times by pro-Palestinian demonstrators highlighting the suffering of civilians in Gaza.

Commenting on the artificial intelligence safety summit in progress in South Korea, Blinken accentuated the positive role of the summit.

"I think these summits can help establish norms, rules, understandings when it comes to safety that could prove invaluable," he said.

"The more we can develop a consensus around what these norms and standards and rules should be, the more we or like-minded countries are in the driver's seat, the more effective we are going to be and making sure that AI is used for good and we minimize its use for bad," he added.

Co-hosted by South Korea and Britain, the two-day summit kicked off on Tuesday. (Yonhap)