WASHINGTON - A federal religious-freedom watchdog panel urged President Bush to boycott the opening ceremonies of the Beijing Olympics unless ''there is substantial improvement'' in China's treatment of Tibet.

The U.S. Commission on International Religious Freedom said China must open ''direct and concrete talks'' with the Dalai Lama, the exiled spiritual and political leader of Tibetan Buddhism, before Bush attends the opening ceremonies.

If those talks do not occur, the nine-member commission called on Bush to first visit the Tibetan capital of Lhasa and urged him to request a meeting with Chinese political prisoners or dissidents during his visit.

''For too long, the Chinese have employed a 'security' approach to Tibetan Buddhism - preferring repression, control of leadership decisions, castigation of the Dalai Lama and 'patriotic education' over freedom of thoughts, conscience and religion,'' said the panel's chairman, Michael Cromartie.

The idea of boycotting the opening ceremonies has been floated by House Speaker Nancy Pelosi and presidential candidate Sen. Hillary Clinton. White House spokesman Tony Fratto told reporters Bush still plans to attend.