BEIJING, July 24 Kyodo - North Korea on Saturday officially rejected a U.S. proposal aimed at breaking the standoff over Pyongyang's nuclear ambitions, calling it ''nothing but a sham offer'' that is ''little worthy to be considered,'' official media reported.

The North instead called on Washington to accept its ''reward for freeze'' proposal, which it claimed enjoys widespread support, the country's official Korean Central News Agency reported.

The comments mark the North's first outright rejection of the U.S. offer, which was made at the third round of six-party talks last month on Pyongyang's nuclear ambitions.

North Korean officials had previous expressed cautious appreciation of the proposal, which features a three-month ''preparatory period'' for dismantling North Korea's nuclear programs and offered incentives if Pyongyang commits to doing away with the programs.

''The U.S. proposal does not reflect at all the principle of 'words for words,' 'action for action' which the U.S. had already promised to observe,'' a spokesman for the North's Foreign Ministry was quoted as saying.

''Moreover, it says nothing of the U.S. commitment to give up its hostile policy toward the DPRK, a stumbling block lying in the way of denuclearizing the Korean Peninsula, and specific ways to do so,'' he said. The DPRK stands for the Democratic People's Republic of Korea, North Korea's official name.

''The DPRK, therefore, considers the U.S. 'landmark proposal' to be little worthy to be discussed any longer,'' the spokesman said.

Denuclearization of the Korean Peninsula can only take place when Washington gives up its ''hostile policy'' toward the North, he said.

The North also slammed U.S. suggestions that it follow the example of Libya and abandon its nuclear weapons.

''The U.S. is foolish enough to calculate that such mode imposed upon Libya would be accepted by the DPRK, too,'' the ministry spokesman said.

Libya pledged in December last year to give up its biological and nuclear weapons programs in exchange for political and economic rewards from the international community.

The spokesman said the only way of solving the nuclear issue is to seek a ''package solution'' based on the principle of simultaneous actions through the North's ''reward for freeze'' proposal made at the June 23-26 six-party talks in Beijing.

Pyongyang uses the phrase ''simultaneous actions'' to mean both sides taking steps at the same time to address conflicting concerns.

North Korea asked for energy aid equivalent to 2,000 megawatts of electricity in return for freezing its nuclear programs as a first step toward dismantling them.

''Whether the U.S. takes part in the project to make reward for the DPRK's nuclear freeze or not is the key to the settlement of the nuclear issue,'' the spokesman said.

''The DPRK's proposal for 'reward for freeze' has enjoyed widespread support and sympathy not only at the six-party talks but from many countries of the world as it is the most reasonable way for a solution to the issue which reflects the actual situation where there is no confidence between the DPRK and the U.S.,'' he said.

''It is a daydream for the U.S. to contemplate forcing the DPRK to lay down arms first under the situation where both are in a state of armistice and at war technically,'' he said.

The nuclear standoff erupted in October 2002 when the United States said North Korea had admitted to running a uranium enrichment program in violation of international agreements, including the 1994 nuclear accord between them.

The accord, known as the Agreed Framework, committed North Korea to freezing and eventually dismantling its plutonium-based, weapons-grade nuclear facilities in exchange for two light-water reactors for power generation and a stopgap fuel supply. ==Kyodo