* Senate Democrats to nix money in $91.3 billion war bill

* Pentagon says needs money to meet goal for closing prison

(Recasts with additional comments)

By Jeremy Pelofsky and Susan Cornwell

WASHINGTON, May 19 (Reuters) - U.S. Senate Democrats on Tuesday moved to cut $80 million earmarked for closing the U.S. prison at Guantanamo Bay, a fresh setback for President Barack Obama's efforts to move beyond the Bush administration's anti-terror policies.

Backpedaling after intense criticism from Republicans and even some Democrats, the White House acknowledged it needed to submit a plan dealing with the 240 terrorism suspects being held at the prison on a U.S. naval base in Cuba.

Obama has pledged to close the prison by early 2010 and asked that $80 million be included in pending legislation that would fund the wars in Iraq and Afghanistan. That measure is expected to pass Congress in the coming days or weeks.

"The president and Congress will work together on a timeline for a renewed request for whatever resources are needed," said White House spokesman Robert Gibbs. "The president still believes it is in our national interest to close Guantanamo Bay."

Obama plans to give a speech on Thursday to further detail his policy on the prison and anti-terror tactics after criticism from rights groups that he has flipped on key promises like ending military tribunals for the detainees and releasing abuse photos.