BEIJING, Jan 12: China and the United States agreed on Monday to step up cooperation on nuclear nonproliferation, security and counter-terrorism just days after North Korea unveiled its nuclear deterrent to a group of US experts.

US Energy Secretary Spencer Abraham inked an agreement with Zhang Huazhu, chairman of the China Atomic Energy Authority, establishing a process to coordinate efforts on nuclear non-proliferation with the UN's International Atomic Energy Agency (IAEA), the US embassy said.

This "is an important step toward accelerating the global effort to reduce the threat posed by the proliferation of weapons of mass destruction," Abraham was quoted as saying in an embassy statement.

The agreement "reflected the commitment from both China and the United States to strengthen efforts to prevent nuclear proliferation and terrorism", the statement said.

The pact would also deepen cooperation on activities covering export controls, international nuclear safeguards, protection of nuclear materials and facilities, nuclear emergency management and radioactive source security.

Cooperation on IAEA international safeguards and nuclear security programmes would also be enhanced. The signing of the "statement of intent" comes after North Korea said it showed its "nuclear deterrent" to two delegations of US experts at its secretive Yongbyon nuclear facility late last week.

The delegations, however, remained tight-lipped over the five-day visit to N. Korea as one of the groups briefed South Korea's assistant unification minister Park Chang-Bong in Seoul on Monday.

The team of US congressional aides Keith Luse and Frank Jannuzi, and another group of US North Korean and nuclear experts, inspected the nuclear complex at Yongbyon, 90km north of Pyongyang, which is at the center of a 15-month crisis over North Korea's nuclear weapons drive.

US newspapers said the delegates appeared to have seen reprocessed plutonium, an ingredient for making nuclear bombs, although Luse said the reports were speculative and warned against drawing "premature" conclusions.

The US-China agreement came as North Korea announced through its state-run news service on Monday that it would freeze its nuclear reactors producing weapons-grade plutonium in exchange for a compensation package from Washington.

China, North Korea's main ally, has been working to resolve the nuclear issue through six-party talks that also include Japan and Russia, but has appeared increasingly impatient with Pyongyang after a hoped-for second round of negotiations failed to materialise in December.

The Tokyo Shimbum reported on Monday that Chinese State Councillor Tang Jiaxuan told Japanese lawmakers the next round of talks could now be held in February. Washington has highly praised Beijing for its efforts to broker the North Korean talks.-AFP