Updated

North Korea has warned fishermen and boat captains to stay away from the country's east coast, Japan's coast guard said Monday, in another sign that the regime is planning to fire medium-range missiles in that area as expected.

But it does not appear ready to test-fire an intercontinental ballistic missile capable of reaching the U.S. from a newly built site despite recent news reports that such a launch may be imminent, South Korean media said.

The medium-range missiles, which put Japan in striking range, are expected to be fired from the coastal town of Anbyon as part of a series of provocative moves following North Korea's May 25 nuclear test and a flurry of short-range missile launches.

On Monday, Japan's coast guard said it picked up a North Korean radio signal banning ships from waters off the North's coastal city of Wonsan near Anbyon from June 10-30.

>> Click to read more on North Korea's nuclear program.

Seoul's mass-circulation JoongAng Ilbo newspaper also said Monday that there have been brisk movements of up to six vehicles mounted with mobile missile launchers at Anbyon over the past week.

The paper and other reports have said that the North could fire Rodong missiles with a range of about 800 miles (1,300 kilometers) or a newly deployed missile that can travel as far as 1,860 miles (3,000 kilometers). Both types of missiles have Japan within striking range.

The paper cited unnamed South Korean government and intelligence officials.

Over on the North's west coast near China, the reclusive regime is said to be assembling an intercontinental ballistic missile.

JoongAng Ilbo said there have been constant movements of personnel and vehicles at the western site, but a missile-tracking radar system has not been installed there yet, indicating a launch is not imminent.

Earlier South Korean media reports had speculated that a launch could come next week -- around June 16 when the presidents of South Korea and the United States are scheduled to hold a summit in Washington.

The timing is being closely watched for signs of further belligerence from North Korea amid fears it could provoke an armed confrontation with South Korea.

U.S. Secretary of State Hillary Rodham Clinton said Washington is considering adding North Korea back to a list of state sponsors of terrorism. The previous administration of President George W. Bush removed Pyongyang from the list last year in exchange for the North's nuclear disarmament pledge.

Clinton was asked on ABC television's "This Week" about a letter that some senators wrote Obama about returning North Korea to that list.

"We're going to look at it. There's a process for it," Clinton said in the interview, taped Thursday in Egypt. "Obviously we would want to see recent evidence of their support for international terrorism."

The JoongAng Ilbo also reported that luxury cars have been spotted moving in and out of North Korea's long-range missile site.

Last week, Tim Brown, a senior fellow with GlobalSecurity.org, said new commercial satellite images have shown that the North's launch site was ready for use after nearly a decade of construction.