Washington  - US President Barack Obama's plans to close the Guantanamo Bay prison camp ran into trouble this week when his own Democrats in the Senate joined opposition Republicans in blocking money to meet one of his top campaign vows.

The Senate followed the lead of the lower House of Representatives by voting 90-6 Wednesday to yank the 80-million-dollar request to shutter the controversial facility from spending legislation for the wars in Iraq and Afghanistan.

Congress insisted that the White House must first offer a plan for closing the facility, but also included in the measure a prohibition on transferring Guantanamo detainees to US soil, a move that could undermine Obama's effort to persuade other countries to accept some of the 240 inmates on the US Navy base in Cuba.

Democratic objections could threaten Obama's order, which he signed two days after taking office, to close the prison by January. Democrats feared a backlash from voters who regard them as softer than their Republican opponents when it comes to national security.

"Democrats under no circumstances will move forward without a comprehensive, responsible plan from the president," said Senator Harry Reid, leader of the centre-left Democrats in the upper chamber. "We will never allow terrorists to be released into the United States."

Obama is even facing resistance within his own administration. The director of the Federal Bureau of Investigation, Robert Mueller, told a House committee on Wednesday that he shares some of the concerns about relocating some detainees to the United States.

Mueller said the FBI would be concerned about the possibility that individuals who may have supported terrorism could provide financial support, radicalize others toward violent extremism or even undertake attacks.

"All of those are relevant concerns," Mueller said.

Even imprisoned detainees could pose a threat, he said, noting that gang leaders often remain capable of running their organizations while locked up.

Obama will seek to regain the momentum in a speech Thursday in Washington on national security. The White House said the president intends to lay out parameters for the difficult decisions that must be made to close the prison.

Presidential spokesman Robert Gibbs acknowledged that lawmakers are justified in opposing the funding until the administration outlines a plan.

"We've made some hasty decisions that are now going to take some time to unwind," Gibbs said. "And closing Guantanamo Bay, obviously, is one of those decisions."

Obama signed the executive order on January 22, one of his first acts as president, designed to show he was serious about reversing some of former president George W Bush's controversial policies, and restoring America's moral standing on human rights. Obama still intends to meet the January timeframe for closing Guantanamo.

"We know that the existence of Guantanamo Bay has become a rallying cry for the very same people that seek to do us harm," Gibbs said. "The president was determined and is determined to ensure that that's no longer a symbol that rallies those that hope to do us harm in the future."

Obama has been seeking help from US allies to close the facility by taking some of the detainees, but so far, only two men have been transferred since Obama took office - one to Britain and another to France.

"When we are asking allies to do their fair share in dealing with this challenge, we have to do our fair share," Michelle Flournoy, the Pentagon's top official for policy, told reporters.

Still, there are some Republicans who flatly oppose closing the camp. They argue it is a state of the art prison facility that is the safest place to keep the detainees, and point out that alleged abuses are a things of the past.

"The idea of giving up that resource is just ludicrous," Senator James Inhofe told reporters.

Obama's executive orders established a task force to sort out how to close Guantanamo. The task force is due to submit a report by July, but for now Obama will be seeking to keep up public support by explaining the complexities of the problem.

Mueller was asked during his testimony whether he had a solution to Guantanamo.

"I don't," he replied. "It's a very difficult issue, and people are honestly wrestling with what the best resolution is." (dpa)