U.S. lawmakers and Afghanistan's opposition forces rallied around the country's former monarch Sunday and vowed to work together to fight their new common enemies: terrorism, Osama bin Laden and the "tyranny" of Taliban rule in Afghanistan.

The unusual encounter occurred in the home of exiled King Mohammad Zahir Shah, who has been trying to unify opponents of the Taliban and help bring a democratic government to the war-ravaged country he left nearly 30 years ago.

The U.S. congressional delegation met under tight security with the former king, members of the Northern Alliance and other anti-Taliban field commanders to offer American support in the campaign to oust Afghanistan's hard-line Islamic regime.

"We let them know we are behind them, and we are together in working for the liberation and eventual freedom for the people of Afghanistan," said Rep. Curt Weldon, a Pennsylvania Republican who heads the 11-member U.S. delegation.

American preparations to respond to the Sept. 11 terrorist attacks have reinvigorated the campaign against the Taliban and turned fresh attention on the long-ignored, reclusive king. The United States has demanded the Taliban turn over bin Laden, the prime suspect.

The king and the alliance commanders said they welcomed the support.

"We have a common struggle against terrorism," the 86-year-old monarch said as he greeted the congressional delegation at his home in Olgiata, a luxurious gated community north of Rome.

The king also gave the United States his tacit approval for a U.S.-led campaign to root out bin Laden as well as the Taliban rulers harboring him, Weldon said.

"His wish is that the U.N. play a role. But he did not dismiss the notion that if the U.N. could not agree, that a U.S.-led force of allies would in fact liberate his country and allow this process to go forward," he said.

Another delegation member, California Republican Rep. Dana Rohrabacher, said the United States does not plan to invade Afghanistan, but merely help Afghans topple the Taliban themselves.

Rohrabacher, a senior member of the House International Relations Committee, said the United States would remain engaged and provide reconstruction aid if the "Taliban tyranny" is unseated.

"We're not going to walk away like we did during the last time when we helped them against the Soviet Union," he said of the U.S. backing for forces that ousted Soviet troops from Afghanistan in the 1980s.

The Bush administration has said little about the congressional delegation, but officials have indicated the United States would support efforts to replace the Taliban.

"We do not want to choose who rules Afghanistan, but we will assist those who seek a peaceful, economically developing Afghanistan free of terrorism," a White House official said Saturday on condition of anonymity.

The new U.S. engagement has sparked an effort to unite the Northern Alliance, which controls a small portion of the country, and other fractious ethnic and religious groups. Much attention has focused on Zahir as a potential unifying force.

Weldon said the monarch was viewed as a "critical" figure in Afghanistan's potential transition and America's efforts to find bin Laden, the reclusive Saudi millionaire blamed for the attacks on the World Trade Center and Pentagon.

Zahir has had a busy week, receiving diplomats from the American and Japanese embassies in Rome and a delegation of conservative British lawmakers as well as a steady stream of Afghan commanders.

Zahir's 1973 overthrow led to the eventual arrival of a pro-Soviet government in Afghanistan and the 1979 Soviet invasion. Soviet troops withdrew in defeat in 1989, and the Taliban seized power in 1996 after devastating fighting between rival groups.