President Barack Obama is pressing lawmakers in the Senate to take another look at ending the military's "Don't Ask, Don't Tell" policy before January, after a vote to repeal the measure failed Thursday.

The proposal to end the ban on gays serving openly in the military failed 57-to-40, three votes short of the 60 needed to advance the measure.

Republican Senator Susan Collins of Maine -- considered to be a crucial swing vote -- ultimately voted in favor of the bill, but failed to bring other Republicans on board.

Democrat Joe Manchin of West Virginia was the only Democrat to vote no on the bill.

In a statement, Obama says he's disappointed senators couldn't pass the new Defense Authorization Bill, which contained a repeal of the controversial policy.

The defeat comes less than two weeks after Defense Secretary Robert Gates and the Chairman of the Joint Chiefs of Staff Admiral Mike Mullen voiced public support for urgent repeal.

The Pentagon also released a highly-anticipated study last week showing two-thirds of soldiers think a repeal won't have a big effect on their unit's fighting abilities.

Meanwhile, senators also delayed action on a measure that would help some undocumented immigrants achieve legal status.

The Senate voted 59-to-40 to table consideration of the so-called "Dream Act."

The legislation would have allowed undocumented immigrants to seek legal status if they were brought to the United States before age 16, have been in the states for five years, and graduated from high school.

They would also have been eligible for citizenship upon joining the military or attending college.

The House passed similar legislation Wednesday to give amnesty to hundreds of thousands of young immigrants.

Critics claimed the act would have encouraged more illegal immigration.

In a statement, the White House says it agrees with the Senate's decision to table its version of the bill in favor of taking up the House's approved version.