U.S. and South Korean officials are privately saying they believe North Korea is preparing a missile launch within the next week.
One U.S. official who requested anonymity told Reuters news agency that increased activity has been detected in North Korea, suggesting that preparations for a launch are being made.
The Japanese government has issued a missile interception order Friday in preparation for such a launch.
Japanese media reported that satellite images show North Korea seems to be setting up a long-range ballistic missile launch from the Tongchang-ri site in western North Korea.
That site is used to fire ballistic missiles that can travel more than 10,000 kilometers. North Korea says the missiles are rockets for launching satellites into space. But South Korea, the United States and other countries suspect Pyongyang is developing missiles that could be used to strike Japan and the U.S.
"The indications are that they are preparing for some kind of launch," one U.S. official told AFP, speaking on condition of anonymity. The official said people on the ground there appear to be readying "a regular space launch."
"Could be for a satellite or a space vehicle - there are a lot of guesses. North Korea does this periodically - they move things back and forth," the official said.
"Our concern though is that they do a space launch but really it's the same technology to develop ICBMs," the official who spoke to Reuters said, referring to intercontinental ballistic missiles.
The area around the launching site has been screened off, and frequent movements of people and vehicles have been observed, according to a
source who spoke to the Japanese news website Yomiuri Shimbun.
A U.N. Security Council resolution bars North Korea from launching ballistic missiles.
The news report came one day after a high-level meeting between the United States in China on sanctions against Kim Jong Un's government for the conducting its fourth nuclear test on January 6.
China remains reluctant
The United States and South Korea have been unable to persuade China to support punishing sanctions against North Korea for continuing its U.N.-banned nuclear program.
After meeting in Beijing Wednesday, U.S. Secretary of State John Kerry and Chinese Foreign Minister Wang Yi both agreed on the need for a “strong” United Nations resolution against North Korea, but they remain divided on how severe the punitive measures should be.
The United States advocates stronger sanctions that restrict shipping, aviation, trade of resources, including fuel, and customs security.
As he has done in the past, Kerry called on China, the North’s key provider of oil and economic assistance, and its principle trading partner, to support sanctions that will impose real economic pain.
"It's not a secret the United States believes very strongly that China has a particular ability because of its special role and its connections to North Korea, an ability to be able to help us significantly to resolve this challenge," Kerry said.
China has expressed strong opposition to North Korea's fourth nuclear test that took place in defiance of U.N. Security Council resolutions, but has been reluctant to support punitive measures that could cause hardship and instability along the Sino-Korean border.
In response to Kerry’s comments, Wang said the U.N. Security Council resolution should be developed with a “responsible attitude” and geared toward resuming international negotiations.
“In the meantime, we must point out that the new resolution is not aiming to provoke tensions and destabilize the [Korean] peninsula, but is aiming to bring the nuclear issue on the peninsula back to the right path, which is dialogue." Wang said.
China and Russia have rejected South Korean President Park Geun-hye's revival of the idea of five-party talks with Washington, Seoul, Tokyo, Beijing and Moscow to develop a strategy to pressure North Korea to give up its nuclear weapon program.
Pyongyang withdrew from six-party talks in 2009 and reneged on a 2005 agreement to dismantle its nuclear program in exchange for economic assistance and security guarantees.
South Korea and the U.S. first suggested five-nation talks, excluding Pyongyang, in 2006, but Moscow and Beijing didn't endorse them.
Rather than recycling past failed approaches, North Korea analyst Cheong Seong-chang with the Sejong Institute in South Korea, said Seoul and Washington must reach a compromise with Beijing.
“In order to bring active cooperation of China and Russia on sanctions against North Korea, it is necessary for South Korea and the U.S. to show active willingness to negotiate with North Korea, not just sanctions,” he said.
Advocates of harsh sanctions, like Bruce Bechtol, a professor of political science at Angelo State University in Texas, say the U.S. already has unilateral sanctions in place that allow authorities to seize assets from third parties that do business with North Korea, which would include many companies in China. Bechtol said President Barack Obama, so far, has been unwilling to take action that would almost certainly lead to increased tensions with Beijing.
Critics of sanctions say they are based on a false idea that North Korea is on the verge of collapse. But given the widespread international condemnation of North Korea’s nuclear test, the prospects of negotiations in the near future seem unlikely.
“This idea of North Korea, which is not going to collapse in popular democratic revolution, which is not going to surrender nukes, and which is not starving, this idea, well, does not sell well in the United States of America,” said Andrei Lankov, a professor of Korean Studies at Kookmin University in Seoul.
VOA's Brian Padden and Youmi Kim in Seoul contributed to this report