|TOKYO : China made a last-minute push to re-start diplomatic talks with North Korea over its nuclear weapons programs, but Pyongyang remained firm on demanding an end to US sanctions before coming back to the bargaining table.
China, impoverished North Korea's main ally, has hosted five rounds of six-nation talks since 2003 to disarm the communist regime, which declared last year it had nuclear weapons.
China is hoping to use a private conference in Tokyo, the first gathering of the six chief envoys since talks broke down in November, to eke out progress ahead of President Hu Jintao's visit to Washington next week.
"I am not certain but there is still some time left," said Chinese envoy Wu Dawei, who reportedly extended his stay by one day until Wednesday.
"There is still a tough situation. Each side intends to make efforts," Wu told reporters after a dinner late Monday with his North Korean counterpart.
South Korean Chun Young-Woo also hoped for a meeting between the two main players in the nuclear crisis.
"We are continuing to make efforts to realize US-North Korea contact. We will have to wait and see. It is premature to make a judgment at this stage," Chun said.
But US chief delegate Christopher Hill has refused to meet bilaterally with North Korea in Tokyo unless Pyongyang returns to the six-way talks.
Hill, the assistant secretary of state for East Asia, later opened one-on-one talks with China's Wu.
"We'll talk and see how and when he can get the Beijing talks going," Hill told reporters.
"This is a big month for our relationship with China. President Hu Jintao is coming to Washington. So we'll have a lot to discuss, a lot of issues in Asia, especially the six-party talks."
North Korea has refused to return to the negotiations - involving China, Japan, the two Koreas, Russia and the United States - since Washington blacklisted a bank for allegedly counterfeiting dollars and money-laundering.
The ban against US institutions dealing with the Macau-based bank are believed to have badly hit the fragile North Korean economy, which is heavily dependent on Chinese aid.
Hill said he felt no need to meet here with North Korean envoy Kim Kye-Gwan as the United States has already met with Pyongyang in Beijing and New York to explain the sanctions.
"I don't have any plan because meetings should have a purpose and we've already discussed our positions," Hill said. "So I'm not sure of the purpose to have a meeting, besides (that) I'm in Tokyo."
The Tokyo conference, which stretches over five days with the main session Tuesday, was organized by the University of California at San Diego to bring together officials and academics from the six nations to brainstorm informally.
It is extremely rare for North Korean officials to visit Japan, which maintains no relations with Pyongyang due to the communist regime's kidnappings of Japanese civilians to train its spies in the 1970s and early 1980s.