The North Korean and Iranian situations are "quite different," a spokesman for North Korea's Foreign Ministry said Tuesday, according to the state-run Korean Central News Agency.
The official reiterated North Korea's assertion that it is a "nuclear weapons state both in name and reality."
"The DPRK is not interested at all in the dialogue to discuss the issue of making it freeze or dismantle its nukes unilaterally first," the spokesperson said, using an abbreviation of the Democratic People's Republic of Korea, the country's official name.
North Korea's nuclear deterrent is "not a plaything to be put on the negotiating table, as it is the essential means to protect its sovereignty and vital rights from the U.S. nuclear threat and hostile policy which have lasted for more than half a century," the official said.
North Korea's 'very dangerous path'
The agreement reached between Iran, the United States and several other nations
aims to prevent Tehran developing a nuclear bomb in return for relief from economic sanctions.
But North Korea's nuclear program is a lot more advanced than Iran's. It has carried out three underground nuclear tests and is believed by many experts to already possess nuclear weapons in some form
One of the key U.S. State Department negotiators with Iran said last week that she hoped the consequences of the agreement "perhaps might give North Korea second thoughts about the very dangerous path that it is currently pursuing."
"This agreement demonstrates that one can come out of isolation, one can come out from under sanctions, one can become part of the world community or have the potential to become part of the world community and end isolation, and do so in a peaceful way," said Under Secretary for Political Affairs Wendy Sherman.
Talks stalled since 2008
Former North Korean leader Kim Jong Il pressed ahead with the country's nuclear program after reneging on an agreement with the United States and other nations to disable its nuclear facilities.
International negotiations over the North Korea's nuclear program, known as the Six-Party Talks, stalled in 2008. The Pyongyang regime has been hit with economic sanctions over its nuclear and rocket tests.
The United States has said that North Korea needs to commit to denuclearization as part of any resumption of negotiations.
"Thus far, they've shown absolutely no interest in pursuing that process through the Six-Party talks," U.S. State Department spokesman John Kirby said at a regular briefing last week.