LONDON - North Korea would give up its nuclear weapons if its national sovereignty were respected and it did not face a nuclear threat, the country's ambassador to Britain said Monday.

But, at the same time, Ambassador Ja Song Nam complained that the world subjected North Korea to double standards and said he doubted there could ever be genuine peace and security while this continued to be the case.

The United Nations Security Council approved expanded sanctions and a trade and arms embargo against North Korea in June after Pyongyang carried out a nuclear test on May 25.

China said Monday its prime minister, Wen Jiabao, would visit reclusive North Korea next week, raising speculation that the trip could help revive stalled talks with global powers on ending Pyongyang's nuclear ambitions.

Talks among the two Koreas, China, Japan, Russia and the United States ground to a halt about a year ago, with Pyongyang saying it would boycott the sessions until Washington dropped its hostile attitude.

North Korea's rejection of the six-party talks did not mean it did not want to de-nuclearize the Korean peninsula, Ja said in a speech at the Royal United Services Institute, a London defense think-tank.

We have rejected the six-party talks because these six-party talks are not based on equality and impartiality, he said, speaking through an interpreter.

If our national sovereignty is respected and if there is no nuclear threat against our country, the nuclear weapons from the DPRK (Democratic People's Republic of Korea) will go, he said.

Our government will try to de-nuclearize the Korean peninsula on the basis of impartiality and equality, he said.

North Korea's neighbors -- China, Russia and South Korea -- were either nuclear states or under the U.S. nuclear umbrella, Ja said.

He said the nuclear issue had arisen because the United States had threatened North Korea with nuclear weapons and because Washington had pursued anti-North Korea policies.

He said it was a double standard to call into question the nuclear test taken by a certain country when established nuclear powers had carried out some 2,000 nuclear tests.

With the continuation of this current status quo, I doubt there can ever be genuine peace and security, he said.

North Korea withdrew from the nuclear non-proliferation treaty in 2003.

(Reporting by Adrian Croft; Editing by Myra MacDonald)