US Secretary of State Condoleezza Rice worked with Japanese leaders Wednesday to coordinate a tough response to North Korea's nuclear test, even as satellite data indicated the North, which has defiantly called sanctions a declaration of war, could be preparing for another test.
Stepping up a flurry of diplomatic activity aimed at getting Washington's allies behind the same message, Rice was to meet with Japan's defense and foreign ministers on Wednesday and Prime Minister Shinzo Abe on Thursday.
The US nuclear envoy, Assistant US Secretary of State Christopher Hill, also arrived in Tokyo on Wednesday. Earlier in the day, in Seoul, he stressed that the international community should make the North pay a "high price" for its "reckless behavior."
Hill told reporters in Seoul he also wanted to talk to South Korean officials about satellite data indicating the North may be getting ready for a second nuclear test. A senior South Korean official, however, told foreign journalists that despite signs of a test, it was unlikely to happen immediately.
Japan is already firmly behind sanctions.
Tokyo is expected to offer naval backup for U.S. military searches of North Korean vessels. Tokyo also plans to expand its sanctions against the North by banning the export of automobiles, liquor and cigarettes to the impoverished regime, the Yomiuri newspaper reported, quoting unidentified officials.
Japan will classify those exports as luxury items banned under UN Security Council sanctions passed over the weekend, the report said. Cars and cigarettes account for 13 percent of Japan's total exports to North Korea, the newspaper said.
A Japanese defense spokesman said the issue of Japan's help with US searches of North Korean ships would be discussed during Rice's visit, but declined to comment on other details of the report. The spokesman was commenting on condition of anonymity according to his department's policy.
Japan last Friday banned North Korean ships and most trade with the communist country under its own sanctions. Participation in military searches of vessels in international seas, however, is a sensitive issue due to Japan's pacifist constitution, which prohibits its armed forces from offensive actions abroad.
So far, the North has been defiant.
North Korea blasted UN sanctions Tuesday aimed at punishing the country for its atomic test on Oct. 9, saying the measures were a declaration of war and that the nation wouldn't cave in to such pressure now that it's a nuclear weapons power.
The statement was the central government's first response to the UN measures approved last weekend.
"The resolution cannot be construed otherwise than a declaration of a war" it said.
The North warned it "wants peace but is not afraid of war" and that it would "deal merciless blows" against anyone who violated its sovereignty.
North Korea on Tuesday marked the 80th anniversary of the "Down-with-Imperialism Union" - a political platform on which the ruling party was built. North Koreans held huge parades and rallies across the country along with an enormous gathering at a central square in Pyongyang.
Enigmatic leader Kim Jong Il attended a performance celebrating the anniversary, the North's Korean Central News Agency reported Wednesday, without specifying when it occurred.
Satellite data has raised concerns that North Korea's nuclear tests might not be over.
U.S. officials said there has been increased activity around at least two other North Korean sites. The activity, which started a number of days ago, includes ground preparation at one site and construction of some buildings and other structures, said the official, who spoke on condition of anonymity because it involved intelligence gathering.
He said although the purpose of the structures is unclear, officials are concerned because North Korea has left open the possibility of another test.
Hill, however, said he doesn't have "any concrete information" on a second test.
After Tokyo, Rice was to visit Seoul.
On her trip, Rice plans to ask South Korea to expand its role in a US-led program to search suspicious ships to stop any efforts by North Korea to spread weapons of mass destruction, Alexander Vershbow, the US ambassador to South Korea, said in Seoul.
South Korea - which has taken a conciliatory approach to the North, including supplying massive amounts of aid - has been reluctant to fully participate in the program, called the Proliferation Security Initiative.
The South worries it could spark clashes with the North, and spoil efforts to persuade the communist state to give up its nuclear ambitions through diplomacy.
South Korea on Wednesday urged the North's restraint.
"We urge North Korea to recognize the international community's clear and firm position ... and not to take any action that is not in line with" the UN resolution, Vice Foreign Minister Lee Kyu-hyung said.