​​​​​​​HAMILTON, Canada 

The US on Tuesday described the capture of two Chinese nationals fighting for Russia in eastern Ukraine as "disturbing."

"We're aware of those reports that Ukraine captured two Chinese citizens fighting on behalf of Russia in Ukraine," State Department spokesperson Tammy Bruce said during a news conference, adding that "it's disturbing with the Chinese soldiers having been captured."

Noting China's support for Russia, Bruce argued that "China is a major enabler of Russia in the war in Ukraine."

"China provides nearly 80% of the dual-use items Russia needs to sustain the war. Eighty percent comes from China," she said.

She echoed concerns about the growing China-Russia alliance. "As President (Donald) Trump has said, continued cooperation between these two nuclear powers will only further contribute to global instability and make the United States and other countries less safe, less secure and less prosperous."

Her remarks came in response to a question on Ukraine announcing the arrest of two Chinese nationals on Tuesday, who were fighting alongside Russian forces in the eastern Donetsk region. The Ukrainian Foreign Ministry later summoned China's charge d'affaires in Kyiv to condemn the alleged presence of its nationals in the country and demand an explanation.