The US Department of Defense warned North Korea Thursday that its arms support to Russia would not only prolong the war in Ukraine but also be tantamount to "directly" joining the killing of innocent Ukrainians.

Deputy Pentagon spokesperson Sabrina Singh made the remarks after this week's summit between North Korean leader Kim Jong-un and Russian President Vladimir Putin raised the prospects of Pyongyang sending more ammunition to Russia for use in the war in Ukraine.

"I think that any country that supports Russia in its unprovoked war in Ukraine is of course going to not only prolong the conflict but is directly engaging in the killing of innocent Ukrainian civilians, officials and those on the battlefield," Singh told a press briefing.

"We have been very public about our warnings to North Korea ... We would encourage that North Korea not pursue a deal with Russia," she added.

Commenting on Russian Defense Minister Sergei Shoigu's recent remarks raising the possibility of joint military exercises with the North, Singh said that potential drills between Pyongyang and Moscow would not affect bilateral or trilateral exercises among Seoul, Washington and Tokyo.

"Following the Camp David summit, you've seen a commitment by all three leaders of each country to continue to engage and support each other," she said. "I don't think any type of exercise between the DPRK and Russia would deter our own advances or our own relationships with ROK or Japan."

DPRK stands for North Korea's official name, the Democratic People's Republic of Korea.

Last month, South Korean President Yoon Suk Yeol and his US and Japanese counterparts, Joe Biden and Fumio Kishida, held the three countries' first-ever standalone trilateral summit at the presidential retreat of Camp David on the outskirts of Washington.

They adopted a series of agreements, including those to commit each other to consult one another in the event of a common threat and hold three-way talks between the leaders, foreign ministers, defense ministers and national security advisers at least annually. ( Yonhap)