US ‘concerned’ over reports of Russia-North Korea nuclear cooperation

National security adviser Jake Sullivan makes comments as US, Japan and South Korea agree to new security pledge

The United States is concerned" about the national security implications of North Korea and Russia reportedly cooperating on nuclear missile technology, the Biden administration said, as the US welcomed the leaders of Japan and South Korea to Camp David on Friday for an unprecedented trilateral summit.

The US, Japan and South Korea agreed to a new security pledge committing the three countries to consult with each other in the event of a security crisis or threat in the Pacific, according to the Biden administration.