The United States has added the Al Qaida-aligned Tawhid and Jihad to its list of foreign terrorists, after a year-long campaign of suicide bombings in Iraq.

Led by Abu Mussib Al Zarqawi, the Tawhid and Jihad group is still regarded as the most lethal insurgent force in Iraq. The group has claimed responsibility for scores of car bombings that have killed more than 1,000 Iraqis in 2003 and 2004.

On Oct. 14, the State Department designated both Tawhid and Jihad as well as Al Zarqawi as foreign terrorists. The United States has asked the United Nations to add the group to its list of terrorists aligned with Al Qaida and subject to international sanctions.

Officials said the U.S. designation would freeze assets of Tawhid as well as Al Zarqawi. If the U.S. designation is approved by the UN, neither Al Zarqawi nor his group would be able to receive funds or resources from member states or their nationals, Middle East Newsline reported.

Officials said the U.S. list of designated Foreign Terrorist Organizations now numbers 39. They acknowledge that many of those under U.S. sanctions have little or no assets that could be seized by Washington or its allies.

The State Department said the main goal of Tawhid was to foment civil war in Iraq. The group has also claimed responsibility for the execution of seven civilians in 2004.

The United States has offered a $25 million reward for information that would lead to the capture of Al Zarqawi. On Saturday, U.S. officials denied a report that Al Zarqawi was captured in the Iraqi city of Faluja, believed to be the stronghold of Tawhid.

Earlier, Tawhid claimed responsibility for suicide attacks on Oct. 14 in Baghdad's so-called Green Zone. The bombings in the fortified zone, which contains the embassies of Britain and the United States, killed up to four U.S. nationals.

"We hope these designations will continue to draw the attention of governments across the world and will encourage those governments to take action, as we have, to isolate these terrorist organizations, to choke off their sources of financial support, and to prevent their members' movement across international borders," State Department spokesman Richard Boucher said.