World powers on Friday urged North Korea to drop plans for a satellite launch in order to save a new deal where Pyongyang halts nuclear and missile activities in return for massive food aid.

The United States, Japan, South Korea and Russia -- partners in troubled nuclear disarmament talks with North Korea -- all condemned the isolated Stalinist state's plan to launch a rocket carrying a satellite next month.

There was no immediate reaction from China, the remaining partner in the six-party negotiations and the one deemed to have the most influence with Pyongyang.

US State Department spokeswoman Victoria Nuland said Washington had "grave concerns" that a February 29 nuclear-missile-and-food deal could be saved after she issued a statement denouncing the satellite launch as "highly provocative."

In her pre-dawn statement, issued just hours after the North Korean announcement, Nuland said the satellite launch would be a threat to regional security and breach a United Nations ban imposed after previous launches.

She told reporters later that US diplomats had "unequivocally" warned their North Korean counterparts in negotiations weeks ago that a satellite launch would be a "deal-breaker" as the rocket amounted to a long-range missile.

Nuland said at stake was President Barack Obama's administration efforts to move ahead on a long-mulled plan to send 240,000 metric tons of food aid to the impoverished state which suffered a famine in the 1990s.

Though food aid was not directly linked to the rest of the deal, she said, the rocket launch raised questions whether Pyongyang had negotiated in "good faith" and could be trusted to carry out the terms for delivering food aid.

"Were we to have a launch, it would create, obviously, tensions and that would make the implementation of any kind of nutritional agreement quite difficult," Nuland said.

"It's very hard to imagine how we would be able to move forward with a regime whose word we have no confidence in and who has egregiously violated its international" obligations, Nuland told reporters.

In a sign of the matter's urgency, Nuland said, Glyn Davies, the US pointman on North Korea, had by daylight spoken over the telephone to all of Washington's partners in the six-party talks, except for North Korea.

"The agreement is for everyone to use their influence with the DPRK (North Korea) to encourage them not to make this launch and not to violate their international obligations and to recommit to the leap day agreement," she said.

In Seoul, the South Korean foreign ministry said a rocket launch would be a "grave, provocative act threatening peace and security on the Korean peninsula" as it would breach UN Security Council resolution 1874.

It urged the North to "immediately stop this provocative act."

In Tokyo, Japan's chief cabinet secretary Osamu Fujimura urged North Korea to abandon its launch plans, saying any rocket firing would be in contravention of international rules and could damage regional stability.

In Moscow, the Russian foreign ministry said the North Korean announcement "provokes serious concern" and urged Pyongyang to reconsider.

In New York, UN Secretary General Ban Ki-moon called on North Korea not to carry out a rocket launch which he warned could breach UN sanctions resolutions.

UN spokesman Martin Nesirky said Ban reaffirmed his call on the North to comply with resolution 1874 from 2009 "which bans 'any launch using ballistic missile technology.'"

UN Security Council Resolution 1874 was passed after the North's second nuclear bomb test in 2009.