White House National Security Council spokesman John Kirby told reporters Wednesday the United States has concerns about any kind of potential defense cooperation between Russia and North Korea.

Kirby said the U.S. is carefully monitoring the contacts between Moscow and Pyongyang.

“No nation on the planet, nobody should be helping Mr. Putin kill innocent Ukrainians. And if they decide to move forward with some sort of arms deals, well, obviously we’ll take a measure of that, and we"ll deal with it appropriately”, - he said.