NKorea rocket 'would break deal'
The United States has warned that it would not send food aid to North Korea if it goes ahead with a rocket launch next month.
US State Department spokeswoman Victoria Nuland said the US now has "grave concerns" about the February 29 agreement that had eased tensions between the long-term adversaries.
Under the accord, Pyongyang agreed to nuclear concessions and a moratorium on long-range missile tests in return for 240,000 tons of American food aid for the impoverished country.
In a surprise announcement, North Korea said it plans to launch a satellite into space on the back of a long-range rocket between April 12 and 16 off its west coast - a provocative step, just as its new leader Kim Jong Un consolidates his power.
The US, South Korea and other critics say the rocket technology overlaps with belligerent uses and condemn the satellite programme as a disguised way of testing military missiles in defiance of a UN ban.
Ms Nuland told a news briefing that a rocket launch would call into question North Korea's good faith and would not create an appropriate environment to go ahead with the food shipments. She added: "We did warn them (North Korea) that we considered that a satellite launch of this kind would be an abrogation of that agreement."
Under it, the North also agreed to allow in inspectors from the UN International Atomic Energy Agency, which have not been able to monitor the North's expanding nuclear programme for three years.
Friday's announcement by the North also will set back prospects for a resumption of six-nation aid-for-disarmament talks that the North withdrew from in 2009.
The Obama administration says it is offering the food aid for humanitarian reasons and denies it is in exchange for the North Korean concessions, a position that may appear less believable if the US now refuses to go ahead with the shipments.
Ms Nuland, however, said an abrogation of the agreement by a launch would call into question the credibility of the North's commitment to allow effective monitoring of food distribution which is intended to prevent diversion of aid from the needy to "regime elites".