North Korea has told its key ally, China, that it is prepared to stage one or even two more nuclear tests this year in an effort to force the United States into diplomatic talks with Pyongyang, said a source with direct knowledge of the message.

Further tests could also be accompanied this year by another rocket launch, said the source who has direct access to the top levels of government in both Beijing and Pyongyang.

The isolated regime conducted its third nuclear test on Tuesday, drawing global condemnation and a stern warning from the United States that it was a threat and a provocation.

“It’s all ready. A fourth and fifth nuclear test and a rocket launch could be conducted soon, possibly this year,” the source said, adding that the fourth nuclear test would be much larger than the third at an equivalent of 10 kilotons of TNT.

The tests will be undertaken, the source said, unless Washington holds talks with North Korea and abandons its policy of what Pyongyang sees as attempts at regime change.

North Korea also reiterated its long-standing desire for the United States to sign a final peace agreement with it and establish diplomatic relations, he said. The North remains technically at war with both the United States and South Korea after the Korean war ended in 1953 with a truce.

Initial estimates of this week’s test from South Korea’s military put its yield at the equivalent of 6-7 kilotons, although a final assessment of yield and what material was used in the explosion may be weeks away.

North Korea’s latest test, its third since 2006, prompted warnings from Washington and others that more sanctions would be imposed on the isolated state. The U.N. Security Council has only just tightened sanctions on Pyongyang after it launched a long-range rocket in December.

The North is banned under U.N. sanctions from developing missile or nuclear technology after its 2006 and 2009 nuclear tests.