Russian Deputy Foreign Minister Sergei Ryabkov has warned about an escalation of tensions over the North Korean nuclear weapons program after Washington toughened its position on Pyongyang.

“It is sad that this powerful element of demands for further pressure on Pyongyang has once again appeared in the American position,” Ryabkov told Russia’s RIA Novosti news agency on Saturday.

“It is high time to stop this race of threats, pressure, blackmail and presentation of preconditions and shift to a real search for a political solution,” he added.

Ryabkov argued that efforts by both Pyongyang and Washington to set preconditions for nuclear talks involved a “risk of uncontrolled escalation.”

During the Friday session of the UN Security Council, US Secretary of State Rex Tillerson backed away from Washington’s earlier offer of unconditional talks with Pyongyang.

On the same day, US President Donald Trump complained that “Russia is not helping” to put pressure on North Korea to end its nuclear weapons program.

Ryabkov noted that “after the UN Security Council session and speeches by senior representatives of Western countries, we got the impression that the logic of pressure is the dominant one in their approach,” warning that the status quo was “extremely dangerous.”

“We would not like to end up in a situation where despite all the efforts by Russia and North Korea and by our two countries jointly, yet another spiral of confrontation begins,” he said.

The Russian diplomat called for “openness and dialogue from both Pyongyang and Washington, mutual restraint and an aim to work out a starting point for a diplomatic step forward.”

China and Russia, North Korea’s main allies, say sanctions will not force North Korean leader Kim Jong-un to increase diplomatic efforts to resolve the conflict.

The standoff over North Korea escalated in July when Pyongyang test-fired two intercontinental ballistic missiles (ICBM). Experts say the entire US mainland is within the range of the missiles, which North Korea says could be equipped with nuclear warheads.

North Korea has been under a raft of crippling UN sanctions since 2006 over its nuclear tests as well as multiple rocket and missile launches. Pyongyang has firmly defended its military program as a deterrent against the hostile policies of the US and its regional allies, including Japan and South Korea.

Trump has vowed to impose additional “major sanctions” against North Korea.

Washington has thousands of troops in the region, partially in South Korea and Japan, and routinely threatens the North with military action to stop its weapons program.