'Incredibly concerning': U.S. denounces Putin's comments on sending weapons to North Korea

The U.S. State Department voiced concern Thursday about remarks by President Vladimir Putin that Russia may provide North Korea with weapons under a new deal between the two nations.

Spokesman Matt Miller said the U.S. is working with allies in Asia to "respond to the threat" by Pyongyang.

"It is incredibly concerning," Miller said at a news conference when asked about the potential of Russia providing North Korea with military assistance.

The Russian president made the remarks Thursday to reporters in Vietnam, one day after concluding a visit to Pyongyang.

"It would destabilize the Korean Peninsula, of course, and potentially give it -- depending on the type of weapons they provide -- might violate UN (Security) Council resolutions that Russia itself has supported, which is why we will continue to work with our allies in the region, South Korea, Japan, others to respond to the threat posed by North Korea," added Miller.

North Korea and Russia vowed earlier to provide each other with military assistance "without delay" if either side is attacked by a third country, under a new partnership agreement inked after a summit between the leaders of the two countries.

The comprehensive strategic partnership treaty was signed Wednesday by North Korean leader Kim Jong-un and Putin after talks in Pyongyang.

The Korean Central News Agency in the North said the treaty requires the sides to not sign deals with third countries that infringe on the other's core interests or participate in such actions.