The United States has offered to open a window of diplomacy with North Korea in a bid to defuse tensions that could set off the ticking time bomb on the Korean peninsula.

US Secretary of State John Kerry said at the end of his four-day Asian tour he would be willing to open a direct US diplomatic channel to the North Korean regime but only if Pyongyang signaled it would move to begin dismantling its nuclear weapons arsenal, reports the Wall Street Journal.

The proposal comes as Washington pushes to de-escalate tensions in the region after scrambling US military forces – including B-2 bombers, F-22 stealth fighters and advanced missile-defence systems.

“We’re prepared to reach out. But we need the appropriate moment, the appropriate circumstances,” Mr. Kerry told reporters Sunday night in Tokyo. “There are standards we need to reach to get to negotiations”.

Washington also urged China to use “all its leverage” to rein in its North Korean ally. China’s top foreign policy official State Councilor Yang Jiechi said it would work with the US to persuade Pyongyang to return to an international diplomatic process, known as six-party talks, after meeting with Kerry in Beijing.

“The most important and key element in all of this is China. China is the only country that can affect North Korean behaviour; they can shut down in a short period their economy,” US Senator John McCain said on CNN’s “State of The Union”.