A top U.S. diplomat has said that a new round of six-party talks on the North Korean nuclear standoff could start later this month. U.S. Assistant Secretary of State James Kelly is on a trip to South Korea and Japan to discuss the North Korea dispute and other security issues.

Mr. Kelly says he is "mildly optimistic" that a fresh round of talks to end the North Korea nuclear crisis will soon be scheduled. After arriving in South Korea on Sunday, he told reporters that the talks could happen as early as this month.

Mr. Kelly is meeting with top South Korean officials, including newly appointed Foreign Minister Ban Ki-moon and Unification Minister Jeong Se-hyun, to discuss the North Korea issue.

The first round of six-nation talks was held in August in Beijing, but ended without resolving the dispute. Efforts to hold a second round have so far been unsuccessful, despite efforts by all five countries engaged in the talks with the North, the United States, South Korea, Japan, Russia and China.

North Korea has said it will freeze its nuclear programs in return for a security guarantee, oil aid, and other concessions from the United States. The Bush administration, however, insists that the isolated Stalinist state verifiably and irreversibly eliminate its nuclear programs before negotiations on any other issues can take place.

Last month, North Korean officials showed an unofficial U.S. delegation what it claimed was plutonium, which can be used to make nuclear weapons. But they denied the U.S. government's statements that the North admitted in October 2002 to running a program to enrich uranium for nuclear bombs. Any nuclear weapons programs in the North would violate its international pledges to be nuclear free.

Mr. Kelly will next travel to Tokyo to meet up with U.S. Deputy Secretary of State Richard Armitage. The two will meet Monday with Japanese leaders on North Korea and other security matters.

North Korean official media on Saturday lashed out at the United States, saying that the U.S. military is flying spy planes over its territory in preparation for an attack. The Unites States has repeatedly said it has no plans to attack the communist nation.

An Australian delegation is now in North Korea to encourage it to hold more talks. Australia, a close U.S. ally, has diplomatic ties with North Korea, while Washington does not.