WASHINGTON: The White House on Friday said North Korea recently provided Russia with a shipment of weapons, calling it a troubling development and raising concerns about the expanded military relationship between the two countries.

The White House showed a series of satellite images that it said indicate cargo from an ammunition depot in North Korea (DPRK) was loaded on to a Russian-flagged ship and then taken by rail to a depot near Russia's southwestern border.

The delivery took place between Sept. 7 and Oct. 1, the US says.

"We condemn the DPRK for providing Russia with this military equipment, which will be used to attack Ukrainian cities, kill Ukrainian civilians, and further Russia's illegitimate war," White House spokesman John Kirby said on Friday.

North Korean leader ends Russia trip with ‘heartfelt thanks’ to Putin

North Korean leader Kim Jong Un and Russian President Vladimir Putin met for a rare summit last month at which they discussed military matters, the war in Ukraine and possible Russian help for the secretive state's satellite programme.

In return for support, North Korea is seeking military assistance from Russia, including fighter aircraft, surface-to-air missiles, armored vehicles and other advanced technologies, Kirby said.

The US is closely monitoring whether Moscow will deliver the weapons, but early signs of Russian ships offloading materials in North Korea may represent initial deliveries, Kirby said.

"This expanding military partnership between the DPRK and Russia, including any technology transfers from Russia to the DPRK, undermines regional stability and the global non-proliferation regime," Kirby said.

The US says it will continue to enforce sanctions, expose the alleged arms deals, and make the case at the United Nations that the actions violate security council resolutions.

"We will not allow the DPRK to aid Russia's war machine in secret. And the world should know about the support that Russia may again may provide the DPRK in return," Kirby said.