By Simon Lewis

NUSA DUA, Indonesia (Reuters) – Chinese Premier Li Keqiang stressed “irresponsibility” regarding nuclear threats during a summit in Cambodia, a senior US official said on Monday, noting that Beijing was uncomfortable with Russia’s strategic nuclear partner’s nuclear rhetoric.

Li attended the East Asia Summit on Sunday with US President Joe Biden. A senior US administration official, who briefed reporters before the summit between Biden and Chinese President Xi Jinping on Monday, said the Chinese premier “spoke fairly extensively about China’s policy toward Ukraine.”

The official, who spoke on condition of anonymity, said Lee “clearly emphasized sovereignty, irresponsibility for nuclear threats, and the need to ensure that nuclear weapons are not used in the way some have suggested.”

The West has accused Russia of making irresponsible statements about the possible use of nuclear weapons since its invasion of Ukraine in February. Moscow, in turn, accused the West of “provocative” nuclear rhetoric.

The US official said there was “undoubtedly some unease in Beijing about what we’ve seen of reckless rhetoric and activity on the part of Russia,” despite the formal partnership with Moscow.

“I think it is undeniable that China may be surprised and even a little embarrassed by the conduct of Russian military operations,” the official said.

Biden said at the summit on Sunday in Cambodia that the United States would “vigorously compete” with China while keeping the lines of communication open to prevent conflict.

Biden and Xi will meet in person on Monday for the first time since Biden took office early last year.

Premier Li is expected to be replaced next year, and the US official said Washington believes Xi will bring “some new faces” to the meeting with Biden on Monday.

(Reporting by Simon Lewis; Additional reporting by Nandita Bose and Humira Pamuk; Editing by Tom Hogg)