U.S. National Security Advisor Jake Sullivan and the secretary general of the North Atlantic Treaty Organization(NATO) have expressed concerns over arms transfers between North Korea and Russia.

According to a press release by the White House, Sullivan and Jens Stoltenberg held talks in Washington on Monday and expressed concern over Russia's procurement of North Korean military equipment, and its use against Ukraine.

The two sides also discussed planning for the NATO summit set for July in Washington and underscored the Allies’ shared commitment to military readiness and the defense of NATO territory.

The White House added that the NATO secretary general reaffirmed the alliance’s unflinching support for Ukraine.