U.N. Secretary-General Kofi Annan Tuesday called for increased diplomatic pressure to bring North Korea back to the six-party talks on giving up the nuclear weapons it claims to have.

"I think we should all work hard to get them back to the six-party talks because that is the only format for the moment that will help us come out of this peacefully," Mr. Annan said. "And all the countries in the region, from China to Japan to South Korea and the Russians, are all pushing in this direction, including Washington."

Returning to headquarters after a trip to Europe, Mr. Annan reminded North Korean leaders that it would be in their economic and political interest to allay international concerns about their stated nuclear program. He urged Pyongyang to be more conciliatory.

"They themselves should also make a gesture," he said. "They should indicate their willingness to give. Because, really, you have three aspects of the problem: you have the nuclear aspect; you have the serious humanitarian situation; and long-term economic development of North Korea. Of course, if this issue were to be resolved, it will have a major impact on the economic development of North Korea and its potential integration into the economies of the region. So there are lots for the North Koreans to gain if this issue were to be settled."

China is said to be preparing a combination of incentives, arguments and mild scare tactics as it tries to persuade North Korea to resume the six-party talks on ending its nuclear program. China's U.N. ambassador, Wang Guangya, says Beijing will not tolerate Pyongyang's refusal to negotiate.

"This is firm. We already told them their statement was unacceptable," he said. "To declare they're a nuclear weapons state, they want to do away with the six-party talks. They want to have talks with the Americans. It is not acceptable."

The six parties - the United States, Russia, China, Japan and the two Koreas - held three rounds of talks beginning in 2003. A fourth round planned for last September did not take place because North Korea refused to attend.

The top U.N. envoy to the Korean peninsula, Maurice Strong, last week predicted Pyongyang would return to the talks. He said a peaceful settlement of the current standoff is essential because, in his words "the consequences of not resolving the issue is so horrendous for all parties."