North Korea pulled out of six-nation nuclear arms talks and announced last month that it has already built a nuclear weapon.
"We need to intensify efforts to not just get the North Koreans back to the table, that's important, yes, but there is a proposal on the table from the United States," Rice said during a news conference en route to Japan.
The United States has offered assurances that it has no intention of attacking North Korea and that Pyongyang can have other unspecified security guarantees if it renounces nuclear weapons.
"There's still no answer to that proposal," Rice said.
The North Koreans must show now "whether seriously they wish to move these talks ahead and whether they are driving toward a strategic decision or not," she said.
The talks hosted by China have been stalled for months, and there are signs that some of the other nations involved are looking for alternatives. Rice reiterated the U.S. position Friday that the six-party talks remain "North Korea's only path to better relations with the rest of the world."
The future of the six-nation talks is on Rice's agenda for meetings this weekend in Japan and South Korea, and on Monday in China. Those nations, plus the United States and Russia, have been negotiating with North Korea.
"It is important to come out and talk with the partners in the six-party talks in light of the North Korean statement" about its nuclear weapon capability, Rice said, but "I don't by any means see it as the central issue of the trip."
Rice will address academics, students and others at a Japanese university this weekend, and press the Bush administration's pledge to spread democracy around the world.
Japan and South Korea are democracies, while communist China is not.
"At a time when the president has said that we're going to put democracy at the center of our dialogue with every country in the world, there's no way that we're not going to raise these issues with the Chinese," Rice said.
Among the other topics Rice said she expects to discuss in Asia are a recent Chinese military buildup and its effect on the balance of power among Pacific powers, and Chinese economic and intellectual property policies.
"We have no problems with a strong, confident, economically powerful China," Rice said.
"Obviously, we still have unresolved differences with China, on human rights, on religious freedom," she added. "We believe that as China becomes a more open economy, more open to the world, that it is going to be a natural development that China is also going to have to open its political system."
Beyond regional security issues, Japan's continuing boycott of U.S. beef imports also was on the agenda here. The ban, which came in response to discovery of a mad-cow problem in the United States, has become the most visible blemish on what has otherwise been an increasingly tight relationship between Tokyo and Washington.
Tensions have flared in recent weeks with growing U.S. calls for quick action to resume the imports. Before the ban, Japan was American beef's most lucrative overseas market.
Japan currently tests all domestic cows for mad cow — also known as bovine spongiform encephalopathy, or BSE — but a government panel has recommended that requirement be loosened to exclude cows 20 months old or younger.
Japan's Food Safety Commission is now working on changing that policy to allow the resumption of beef imports from younger U.S. cows.
The United States is pushing for quick action, and some members of the U.S. Congress have warned of possible sanctions if Japan does not lift the ban soon.
Japanese officials, however, have refused to set a timetable for the resumption of imports, saying the commission should be allowed to complete its work.
Japanese Prime Minister Junichiro Koizumi on Thursday denied that Japan was dragging its feet on lifting the ban, saying food safety was of paramount importance.
Eating infected beef can lead to the brain disease's fatal human variant, Creutzfeldt-Jakob disease.