Kim made the comments during his first summit with Russia's Vladimir Putin on Thursday in Vladivostok, the Korean Central News Agency reported, describing their talks as "unreserved and friendly".

The comments also came about a week after Pyongyang demanded the removal of Secretary of State Mike Pompeo from stalled nuclear talks with Washington, accusing him of derailing the process.

The North Korean leader said "the situation on the Korean peninsula and the region is now at a standstill and has reached a critical point", KCNA said.

Kim warned that the situation "may return to its original state as the US took an unilateral attitude in bad faith at the recent second DPRK-US summit talks", the agency added.

The Kim-Trump summit broke down in late February without a deal on North Korea's nuclear arsenal.

At those talks, cash-strapped North Korea demanded immediate relief from sanctions, but the two sides disagreed over what Pyongyang was prepared to give up in return.

Kim told Putin that the "DPRK will gird itself for every possible situation", KCNA said.

The North Korean leader invited Putin to visit North Korea "at a convenient time" and the invitation was "readily accepted", the agency said in one of several dispatches about the summit.

During his talks with Kim on Thursday, Putin positioned himself as a counterweight to the United States, insisting that the North needed "guarantees of its security, the preservation of its sovereignty".

"We need to... return to a state where international law, not the law of the strongest, determines the situation in the world," Putin said.

Kim said he hoped to usher in a "new heyday" in ties between Pyongyang and Moscow.

The pair "were unanimous" that their meeting could help in "strategically controlling the unstable situation of the Korean peninsula in the wake of the second DPRK-US summit talks", it said.