The Bush administration has added the Southeast Asian Muslim extremist group Jemaah Islamiya to its list of foreign terrorist organizations. The group is a prime suspect in the October 12 terrorist bombings in Bali, Indonesia, though U.S. officials say their decision does not mean investigators have solved the case.

The decision on Jemaah Islamiya, announced in the U.S. government journal The Federal Register, had been under consideration for several months.

But a senior State Department official says the Bali bombings, which killed nearly 200 people, gave added impetus to the process.

The designation as a terrorist organization freezes assets Jemaah Islamiya may have in the United States, prevents it from raising money in this country, and bars its members from getting U.S. visas.

In a written statement, Secretary of State Colin Powell said the United States is also joining 12 Asian countries, including Indonesia, in asking the United Nations to place the group on U.N. anti-terrorism blacklists.

He said the joint referral is a "powerful signal" that countries of Southeast Asia will not tolerate terrorism on their soil, and are committed to working with the international community "to put a stop to wanton acts of terror."

Mr. Powell said he hopes the combined steps will put Jemaah Islamiya "out of the terrorism business."

The Secretary said the United States and its allies have long had concerns about the activities of Jemaah Islamiya, and that the moves are not meant to imply that they have come to a conclusion about responsibility for the devastating Bali attacks.

The senior official who spoke to reporters said much of the U-S evidence against Jemaah Islamiya is classified.

But he noted that authorities in Singapore and Malaysia have arrested members of the group for plotting attacks against American and other western interests. He said information recovered by U.S. forces in Afghanistan indicates links between Jemaah Islamiya and al-Qaida.

Jemaah Islamiya seeks to create a single Islamic state including Indonesia, Malaysia, Singapore and the southern Philippines, and it received prominent mention in the State Department's most recent report on global terrorism issued last May.

Later this week, President Bush is to meet Indonesian President Megawati Sukarnoputri at the Pacific-rim summit in Mexico and push for a tougher approach against such groups.

But the senior official said timing of the U.S. move and the Mexico meeting was coincidental.