Updated

North Korea is accelerating preparations for testing a missile that has the potential to strike the United States, a U.S. government official said Friday. A test of the Taepodong-2 long-range missile may be imminent, the official said.

The official agreed to speak but only on the condition of anonymity because of the sensitivity of the information.

The official said the Bush administration is very concerned about activities that point toward a test, but declined to elaborate.

Japanese and South Korean officials also have expressed concern in recent days about the reported North Korean missile launch activities. Kyodo News agency in Japan reported that an additional rocket section had arrived at a North Korean launch site within the past two days.

In Tokyo, the Japanese government responded to news reports about a possible test by warning that any such step would jeopardize the country's security.

The reports of a possible launch come after a prolonged hiatus in six-party nuclear disarmament talks designed to create a Korean peninsula free of nuclear weapons.

Persistent efforts by the United States and other members of the group to persuade North Korea to resume the discussions have not been successful. There have been no discussions since last November.

CountryWatch: North Korea