The second phase of the six-party talks on peacefully dismantling North Korea's nuclear weapons programme resumed on Monday after a year-long hiatus.
The delegations of North Korea, the United States, South Korea, China, Russia and Japan gathered at the Diaoyutai State Guest House and will have bilateral and multilateral modes of talks, diplomatic sources said.
Launched in 2003, the six-party talks have been held for five rounds.
However, the talks have remained on hold since the DPRK (the Democratic People's Republic of Korea) walked out of the negotiations more than a year ago in response to US sanctions for alleged money laundering through banks in Macao, a Chinese territory.
The second phase of the fifth round of the six-party talks has commenced after its last session in November 2005.
Pyongyang agreed in principle to dismantle its nuclear weapons at the September 2005.
On Sunday, the United States insisted that North Korea should get out of the "nuclear business" if the sanctions had to be lifted.
"The DPRK needs to get serious about the denuclearisation issue," US assistant secretary of state for East Asian and Pacific affairs Christopher Hill said, adding "a lot of good things" could happen if Pyongyang gets serious about the denuclearisation issue.
"I'm here to do more progress on the September, 2005 agreement," Hill, the top US negotiator for the six party talks, said.
"If they want to get out of the sanctions, they should denuclearise," Hill stressed.
Hill said the United States, together with China and Russia, had told Pyongyang many times in many occasions that they don't accept the country as a nuclear state.
Concerning the financial sanctions against North Korea, Hill said it is not a focus of the six-party talks.
The talks should fix on the implementation of the joint statement adopted by all parties concerned in September, 2005.
Hill's statement came after North Korea's top envoy, Kim Kye-gwan on Monday ruled out dismantling its nuclear weapons unilaterally in the face of "hostile" policies against Pyongyang.
Kim said North Korea was not optimistic about the outlook of the latest round of six party talks, and the United States should change its hostile policy towards Pyongyang to peaceful co-existence policy.
Kim, also vice foreign minister of North Korea said his side is willing to discuss other contents of the September Joint Statement except the nuclear weapons during the new round of six-party talks, under the circumstances that the United States gives up its economic sanctions against his country.
Kim said the DPRK will not give up the nuclear weapons, which are against the US invasion and threat.