Trying to unsettle President Saddam Hussein, small groups of American diplomats and intelligence analysts infiltrate northern Iraq periodically to confer with Kurds and other opponents of the Baghdad government, U.S. officials confirmed Tuesday.

With the area protected by U.S. and British overflights and beyond the reach of Saddam's air force, the American forays are part of an unabashed, mostly psychological campaign to rattle him.

At this stage, the main Iraqi opposition group, the Iraqi National Congress, has not produced any plan that holds promise of success, a senior U.S. official said. As a result, the United States has not approved any military move inside the country and is not attempting one of its own.

The Defense Department on Tuesday denied rumors that any U.S. ground troops were inside Iraq. Lt. Col. Dave Lapan, a Pentagon spokesman, said the rumors had apparently originated with a Fox News Channel report of U.S. covert activity inside Iraq.

President Bush is considering military as well as diplomatic and political tactics to try to end the rule of a leader he denounced last month as part of an "axis of evil."

U.S. air patrols of Iraq's no-fly zones have remained constant since Sept. 11, when terrorists struck the World Trade Center and the Pentagon and touched off a worldwide campaign against terror groups and countries that support them.

Saddam's refusal to admit U.N. weapons inspectors for more than three years has heightened concern over his programs to develop weapons of mass destruction. Combined with Iraq's support for terror — it is one of seven countries so branded by the State Department — the threat is considered unequalled by administration analysts.

Still, U.S. warplanes have launched fewer retaliatory strikes against Iraqi targets since Sept. 11 because the Iraqis are firing at the U.S. planes less frequently, Lapan said.

In December, a State Department group headed by American diplomat Ryan Crocker went to northern Iraq to help pull together Kurdish and other anti-Saddam forces.

It was the last such trip by U.S. officials, but there were several earlier and they are likely to happen again, said a U.S. official, speaking on condition of anonymity.

Secretary of Defense Donald H. Rumsfeld said Sunday that "very small numbers" of Americans from various departments were involved.

Late last year, a bipartisan group of nine members of Congress asked Bush to support Iraqi opposition forces with humanitarian assistance, information gathering and military training.

The lawmakers said in a letter to the president that U.S. efforts to replace Saddam would not succeed without the help of allies on the ground inside Iraq. They suggested the support should be directed to the London-based Iraqi National Congress, the umbrella organization for all major groups opposed to Saddam.

Previous administrations have denied U.S. assistance for the INC to carry out operations inside Iraq.

The Bush administration, however, has funded an information collection program and humanitarian aid offices in New York and Washington, but the opposition group has not provided a plan for distributing the assistance.

Under a congressional grant, some non-lethal training has been provided. In all, the Iraqi National Congress has received $12.4 million since 1998.