U.S. President Joe Biden has voiced concern over North Korea's illicit ballistic missile and nuclear programs during summit talks with Chinese President Xi Jinping.

Sarah Beran, the White House National Security Council's(NSC) Senior Director for China and Taiwan Affairs, said on Thursday that the U.S. has expressed its focused concerns over strengthened North Korea-Russia ties through various other channels of communication with China.

Beran said Washington and Beijing have held discussions on the implications of Pyongyang-Moscow relations on the denuclearization of the Korean Peninsula, Russia's duties as a permanent UN Security Council member and a possible nuclear test by the North.

The NSC official said the U.S. has been consistent in raising concerns and urging China to seriously consider the impact on regional security.

U.S. Assistant Secretary of State for East Asian and Pacific Affairs Daniel Kritenbrink said Washington has called on China to focus on the peninsula's denuclearization at all high-level dialogues with Beijing over the past six months.

He added that Washington also reminded Beijing of its ironclad defense pledge to regional allies South Korea and Japan.

[Photo : KBS]