North Korea on Saturday criticised the US suspension of food aid over its planned rocket launch as an "overreaction", warning it would render last month's deal on a nuclear freeze null and void.

"The U.S. overreaction to the DPRK (North Korea's) plan... has gone beyond the limit," a foreign ministry spokesman said, according to the North's official news agency KCNA.

He said that Washington had previously insisted that it made no link between humanitarian and political issues.

But it had responded to the "planned satellite launch with the announcement to stop following through on its commitment to food aid," the spokesman continued.

"This would be a regrettable act of scrapping the DPRK-U.S. agreement in its entirety as it is a violation of the core articles of the February 29 DPRK-U.S. agreement."

The United States announced Wednesday that it had suspended plans to send food aid to the nuclear-armed North as it had broken a promise to halt missile launches and could not be trusted to give the help to those who needed it.

A Pentagon official said the US had "no confidence" that it was possible "to ensure that the food assistance goes to the starving people and not the regime elite".

Under the US-North Korea deal, the impoverished North had agreed to a partial nuclear freeze and a missile test moratorium in return for 240,000 tonnes of US food aid.

But not long after it was agreed, the North announced it planned to launch a satellite between April 12-16 to mark the 100th anniversary of the birth of founding president Kim Il-Sung.

The United States and other countries say it would in fact be a long-range missile test banned under UN resolutions.

"This planned launch is highly provocative because it manifests North Korea's desire to test and expand its long-range missile capability," said Peter Lavoy, acting assistant secretary of defense for Asian and Pacific affairs, on Wednesday.

During discussions with the North, the US had made it "very clear" that a satellite launch would be a "deal breaker", he said.

In Saturday's statement, the foreign ministry spokesman said that the North was yet to make its mind up about its final response to the US suspension of food aid, and urged Washington to reconsider the move.

"(North Korea) just hopes that the U.S. would courageously accept peaceful satellite launch by a sovereign state, though belatedly, and prove in practice its words that it has no hostility toward the DPRK," he said.