Secretary of State Condoleezza Rice (search) pressed Japan to end a costly boycott on U.S. beef Saturday, saying "American beef is safe."

She also offered support for Japanese membership in the U.N. Security Council (search) as she prepared to visit South Korea, trying to take a less confrontational approach to persuading North Korea to return to international nuclear disarmament talks.

North Korea complained that Rice unfairly labeled the country an "outpost of tyranny" earlier this year and demanded an apology. Rice aims to stay out of rhetorical arguments that North Korea (search) can use as an excuse for delay, according to officials accompanying her on a weeklong Asian trip.

Her speech at Tokyo's Sophia University (search) was intended as a statement of U.S. foreign policy goals in Asia and commitment to spread democratic principles, even in communist China, officials said.

Rice told the Japanese that their ban on U.S. beef flouts scientific agreement on beef safety and endangers broader trade that both nations value.

"The time has come to solve this problem," she said. "I want to assure you American beef is safe and we care deeply about the safety of food for the world."

The Japanese ban, in response to discovery of a cow infected with mad cow disease in the United States, has become the most visible blemish on what has otherwise been an increasingly good relationship between Tokyo and Washington.

Tensions have grown in recent weeks with rising U.S. calls for quick action to resume the imports. Before the ban, Japan was American beef's most lucrative overseas market.

At a news conference later, Rice and Japanese Foreign Minister Nobutaka Machimura both said they discussed U.S. concerns over the ban.

"I made the point that this has gone on a long time," Rice said. "This a very, very important concern of the U.S. government."

Machimura said, however, that he could not offer any guarantee for when beef imports would resume.

As for North Korea, Rice indicated before Saturday's speech that the next move in a standoff over nuclear weapons would be up to the Pyongyang government, and she played down expectations that her visit to Asian capitals will produce a breakthrough.

North Korea pulled out of six-nation nuclear arms talks and announced last month that it has already built a nuclear weapon.

Answering questions from the audience after her speech Saturday, Rice said she knows there is some international frustration with the slow pace of North Korean talks. But she said the six-party discussions remain the best option. She rejected a suggestion that the United States might make more progress if it dealt with North Korea one-on-one.

"We bring different incentives, different leverage to North Korea, each of us ... I would be first to admit it is not easy to deal with North Korea," Rice said.

The United States has said it has no intention of attacking North Korea and that Pyongyang can have other unspecified security guarantees if it renounces nuclear weapons.

Rice said at the news conference that she would appeal for additional Chinese help in bringing the North Koreans back to the negotiating table. "We are committed to diplomacy, but I think it goes without saying that no one is just going to allow the North Koreans to go down a path" that threatens the entire region.

Concerning the U.N. Security Council, permanent membership is a long-standing Japanese goal. Rice's endorsement was the most explicit statement yet of U.S. support for Japan's request.

"Japan has earned its honorable place among the nations of the world by its own effort and by its own character," Rice said in her speech. "That is why the United States unambiguously supports a permanent seat for Japan on the United Nations Security Council."

Rice also proposed that Japan and the United States cooperate on distribution of international development aid, focusing on countries that accept their own share of responsibility.