SEOUL, DEC. 18 -- South Korean President Roh Tae Woo declared publicly tonight that there are now no U.S. nuclear weapons in his country, and he called on North Korea to immediately abandon its nuclear-weapons development program.

In a televised 10-minute speech to the nation, Roh said, "As I speak, there do not exist any nuclear weapons whatsoever anywhere in the Republic of Korea."

He added that North Korea now has "no reason or excuse" to develop nuclear weapons or refuse international inspections of its nuclear facilities. "North Korea must immediately abandon the development of nuclear weapons," he said. "It is an imperative duty that cannot and should not be delayed."

The United States, South Korea, Japan and other nations say they believe that North Korea is not far from being able to build an atomic bomb.

North Korea contends that its nuclear program is peaceful, and it has signed the Nuclear Non-Proliferation Treaty. But so far, North Korea has refused to sign the follow-up Nuclear Safeguards Agreement, which would allow international inspections of its nuclear facilities.

{In Washington, State Department spokesman Richard Boucher said the United States welcomed Roh's statement, Reuter reported. "We have supported President Roh's call earlier for a non-nuclear peninsula, and we're prepared to cooperate with his plan for mutual inspections, to verify the absence of nuclear weapons and of reprocessing and enrichment facilities," he said.

{He called on North Korea to "open its facilities to inspection . . . to abandon any plans it has for nuclear reprocessing or enrichment, to forswear the development of nuclear weapons, and to abide by its international obligations."}

In recent weeks, North Korean officials have said they would sign the safeguards agreement and allow inspections once they have been notified that U.S. weapons have been removed from South Korea.

In his speech, Roh also reaffirmed South Korea's full support of last week's historic pact with the North on nonaggression and reconciliation.

Critics in South Korea have charged that Seoul should have made settlement of the nuclear issue a precondition to signing the agreement. In reaching the nonaggression accord, the two Koreas agreed to take up the nuclear issue next week at the border truce village of Panmunjom.

Tonight, Roh said he hoped that the two Koreas could settle the nuclear issue by the end of the month.

Meanwhile, U.S. Rep. Steven J. Solarz (D-N.Y.), chairman of the House Foreign Affairs subcommittee on Asian and Pacific Affairs, is expected to wind up a trip to Pyongyang today. Japanese news reports said Solarz was to have met with North Korean President Kim Il Sung and Foreign Minister Kim Yong Nam.