Following Sergei Shoigu's arrival on a rare trip to Pyongyang, Blinken said that Russia is scrambling to buy arm from allies across the world.

"I strongly doubt he's there on holiday," Blinken told reporters in Australia.

"We're seeing Russia desperately looking for support, for weapons, wherever it can find them to continue to prosecute its aggression against Ukraine," he said.

"We see that in North Korea, we see that as well with Iran, which has provided many drones to Russia that it's using to destroy civilian infrastructure and killed civilians in Ukraine."

While in North Korea, Shoigu met the country's leader Kim Jong Un, in what Pyongyang's state media described as "a friendly talk."

Russia, a historic ally of North Korea, is one of a handful of nations with which Pyongyang maintains friendly relations.