Updated

The five permanent members of the U.N. Security Council and Japan agreed Monday to continue discussions on a resolution against North Korea in response to missile tests that rattled the region last week.

The Tokyo-sponsored resolution that calls for sanctions would have to be altered for the council to approve it, China's ambassador told reporters after a meeting with envoys from the United States, Russia, Britain, France and Japan.

"If they wish to have a resolution, they should have a modified one, not this one," Ambassador Wang Guangya said.

China's consideration of any resolution was considered significant since Beijing had been pressing for a presidential statement, which is not legally binding.

U.S. Ambassador John Bolton said any Chinese suggestions for changes would be considered, and the council would re-evaluate whether to proceed with a vote "on a daily basis."

"We felt withholding actions in the Security Council to allow Chinese diplomacy to proceed makes a lot of sense," Bolton said.

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CountryWatch: North Korea

The Kyodo News agency, citing unidentified Japanese officials, reported that Japan and the United States were seeking a renewed moratorium by North Korea on missile testing, and its unconditional return to six-party talks on its nuclear program, in exchange for no sanctions.

Bolton said the United States wants North Korea to return to the talks and resume the moratorium on missile testing, among other measures. But he refused to say whether the United States would agree to drop sanctions if North Korea did so.

The Japanese draft under Chapter 7 of the U.N. Charter, which allows military enforcement, demands that North Korea immediately stop developing, testing, deploying and selling ballistic missiles.

It also bans all U.N. member states from acquiring North Korean missiles or weapons of mass destruction — or the parts or technology to produce them — and orders all countries to take steps to prevent any material, technology or money for missile or weapons programs from reaching the North.

The draft resolution also urges North Korea to return immediately to the talks on its nuclear program with the United States, Japan, South Korea, China and Russia. The talks have been stalled since September.

The United States, Britain and France have expressed support for the proposal, while Japanese Foreign Minister Taro Aso has said there is a possibility that Russia will abstain.

Japan said Monday it was considering whether a pre-emptive strike on North Korea's missile bases would violate its constitution, signaling a hardening stance ahead of a possible Security Council vote.

Japanese Prime Minister Junichiro Koizumi told reporters his government wants a vote on the measure "as soon as possible."

"I think we must send a message that's as clear as possible" to North Korea, he said.

Japan was badly rattled by North Korea's missile tests and several government officials openly discussed whether the country ought to take steps to better defend itself, including setting up the legal framework to allow Tokyo to launch a pre-emptive strike against Northern missile sites.

"If we accept that there is no other option to prevent an attack ... there is the view that attacking the launch base of the guided missiles is within the constitutional right of self-defense. We need to deepen discussion," Chief Cabinet Secretary Shinzo Abe said.

Japan's constitution bars the use of military force in settling international disputes and prohibits Japan from maintaining a military for warfare. Tokyo has interpreted that to mean it can have armed troops to protect itself.

A Defense Agency spokeswoman, however, said Japan has no offensive weapons such as ballistic missiles that could reach North Korea.

Japanese fighter jets and pilots are not capable of carrying out such an attack, a military analyst said.

"Japan's air force is top class in defending the nation's airspace, but attacking another country is almost impossible," said analyst Kazuhisa Ogawa. "Japan has no capacity to wage war."

South Korea, not a council member, has not publicly taken a position on the sanctions resolution, but on Sunday Seoul rebuked Japan for its outspoken criticism of the tests.

Meanwhile, a Chinese delegation including the country's top nuclear envoy — Vice Foreign Minister Wu Dawei — arrived Monday in North Korea, officially to attend celebrations marking the 45th anniversary of a friendship treaty between the North and China.

The U.S. is urging Beijing to push its communist ally back into six-party nuclear disarmament talks, but the Chinese government has not said whether Wu would bring up the negotiations. A ministry spokeswoman said last week that China was "making assiduous efforts" in pushing for the talks to resume.

Talks have been deadlocked since November because of a boycott by Pyongyang in protest of a crackdown by Washington on the regime's alleged money-laundering and other financial crimes.

Beijing has suggested an informal gathering of the six nations, which could allow the North to technically stand by its boycott, but at the same time meet with the other five parties. The U.S. has backed the idea and said Washington could meet with the North on the sidelines of such a meeting.

Still, Assistant Secretary of State Christopher Hill questioned just how influential Beijing was with the enigmatic regime.

"I must say the issue of China's influence on DPRK is one that concerns us," Hill told reporters in Tokyo. "China said to the DPRK, 'Don't fire those missiles,' but the DPRK fired them. So I think everybody, especially the Chinese, are a little bit worried about it."

The DPRK refers to the North's official name, the Democratic People's Republic of Korea.

Hill is touring the region to coordinate strategy on North Korea. He has emphasized the need for countries involved to present a united front.

"We want to make it very clear that we all speak in one voice on this provocative action by the North Koreans to launch missiles in all shapes and sizes," Hill said. "We want to make it clear to North Korea that what it did was really unacceptable."

The Associated Press contributed to this report.