LONDON (AP) _ North Korea is developing two new ballistic missiles, one possibly capable of reaching the U.S. territory of Guam, Jane's Defense Weekly said Wednesday in a report quoting U.S. intelligence sources.

Last month, American intelligence satellites detected what are believed to be full-scale mock-ups of the two new missiles at the Sanum Dong research and development facility on North Korea's northeast coast, it said.

''The Americans are not sure whether the missiles are in development or production, but Japanese sources indicated that both of the missiles are likely to fly before 1998,'' Paul Beaver, senior publisher for Jane's Information Group, told The Associated Press.

North Korea's development of long-range ballistic missiles would have serious implications for nations in the Asia-Pacific region. Whether the isolated Communist nation is capable of putting nuclear weapons atop those missiles remains a key question.

International inspectors are in North Korea checking its nuclear facilities. Pyongyang insists its nuclear program is peaceful but Western intelligence suspects North Korea is trying to build nuclear weapons.

''The fact that North Korea is prepared to spend money developing an intercontinental ballistic missile capability indicates they are serious in their power projection in the region,'' Beaver said.

This will have a bearing on discussions between Tokyo and Washington on whether the United States should give Japan the technology to develop a missile defense system against ballistic missiles like those being developed by North Korea, he said.

Last week, Army Gen. Gary E. Luck, the commander of U.S. forces in South Korea, told Congress that North Korea possessed an improved ballistic missile arsenal.

The CIA disclosed in July that North Korea had tested a surface-to-surface missile with an estimated range of 620 miles. The United States calls it the Nodong 1.

Jane's Defense Weekly, in its report from Washington, said the two new missiles, called Taepo Dong-1 and Taepo Dong-2, have ranges of 1,250 miles and up to 2,190 miles, respectively.

North Korea would need a range of 2,190 miles to attack Guam, the largest and most southern of the Mariana Islands in the western Pacific. The United States has Air Force and naval facilities on Guam, which it retook from Japan in 1944.

According to Jane's, non-government analysts reviewing the intelligence data questioned whether Taepo-Dong 2 could reach Guam.

Without test flights, Beaver said, it is difficult to verify the range.

''Up until now, the North Koreans have just been stretching the Soviet Scud into a single-stage missile like Nodong 1,'' he said.

''What they're doing now is to develop two-stage missiles, initially by adding two single-stage missiles together and eventually by developing them from scratch.''

North Korea is also reportedly developing a two-stage ballistic missile called Nodong 2 with financing from Iran. According to diplomatic sources in Cyprus, North Korea's air force commander led a 29-man mission to Iran in February apparently to discuss test-firing the Nodong 2.

Beaver said there is some confusion over missile names, but Jane's believes the North Koreans may be developing two different series of missiles - the Nodong stream and the Taepo-Dong stream.

Jane's said the U.S. satellite intelligence photos also revealed a Silkworm anti-ship cruise missile and launcher, a Russian SA-2 anti-aircraft missile, and a Russian T-62 tank at Sanum Dong.