North Korea's key ally China on Thursday welcomed Pyongyang's announcement that it will suspend its nuclear tests and uranium enrichment programme in return for US food aid.

The deal -- which came less than three months after the death of North Korean leader Kim Jong-Il -- follows talks held in Beijing last week between the United States and North Korean negotiators.

The Pyongyang regime, led by Kim's young and untested son Kim Jong-Un, also promised late Wednesday to suspend long-range missile tests and allow UN nuclear inspectors back to monitor the moratorium on uranium enrichment.

"We welcome the improvement in relations between North Korea and the United States and their contributions to maintaining peace and stability on the Korean peninsula," said Chinese foreign ministry spokesman Hong Lei in a statement.

"China is willing to work with relevant parties to continue to push forward the six-party talks process, and play a constructive role to realise long-term peace and stability on the Korean peninsula and north-east Asia."

North Korea abandoned six-nation talks on ending its nuclear weapons programme in April 2009 because of what it described as US hostility and conducted a nuclear test the following month, to international condemnation.

The United States has been exploring a resumption of the negotiations, which are chaired by China and also include Japan, the two Koreas, Russia and the United States.

In Wednesday's agreement, the United States and North Korea also reaffirmed their commitment to a September 2005 six-nation deal.

This envisaged the North scrapping its nuclear programmes in return for major diplomatic and economic benefits and for a peace treaty formally ending the 1950-53 Korean War.