South Korea's president says North Korea must abandon efforts to build nuclear weapons. The demand comes just after Pyongyang announced it was scrapping an agreement to keep the Korean Peninsula nuclear free. President Roh Moo-hyun says Pyongyang's pursuit of nuclear weapons will determine if relations between the two Koreas improve.

Mr. Roh, in a speech while visiting New York, called on North Korea to give up its nuclear weapons programs and re-admit international nuclear inspectors. The president, in his remarks to the Korea Society, said North Korea has a choice of going "down a blind alley or it can open up."

The trip is Mr. Roh's first overseas since taking office in February. He meets with President Bush in Washington on Wednesday, to discuss their governments' differences responding to North Korea's quest to obtain nuclear weapons. South Korea favors a more conciliatory approach to North Korea than the Bush administration has taken so far. Both governments, however, stress they want the issue resolved peacefully.

North Korea's official news agency says a 1992 declaration between North and South Korea to keep their countries free of nuclear weapons is now a "dead document." It was the North's last international agreement to remain nuclear free.

A spokeswoman for President Roh says the North Korean statement might be a negotiating ploy in the aftermath of talks held last month in Beijing with U.S. officials. During that meeting, North Korean delegates reportedly admitted their country has nuclear bombs.

North Korea expert Tim Savage says Pyongyang's rejection of the agreement comes as no surprise. "This is the same game that has been played out for months. The North Koreans keep trying to up the ante to force the U.S. to the negotiating table," he says. "The Bush administration continues to refuse to engage in any serious dialogue."

In the past few months, Pyongyang pulled out of the global non-proliferation Treaty and a 1994 agreement with the United States to give up its nuclear weapons programs in return for energy aid.

Last October, the United States said North Korea had admitted having a secret nuclear weapons program, in violation of its international commitments. Since then, tensions have risen on the Korean Peninsula, with the North issuing a stream of threatening rhetoric.