* Obama to deliver prime-time address on Wednesday
* President faces pressure for Afghanistan endgame (Adds Kerry comment, details and background)
By Matt Spetalnick and Susan Cornwell
WASHINGTON, June 21 (Reuters) - President Barack Obama is expected to unveil plans to remove about 5,000 U.S. troops from Afghanistan in July and up to 5,000 more by year-end as he lays out a broader withdrawal blueprint on Wednesday to Americans increasingly weary of the costly, decade-old war.
Obama will announce the first phase of a promised drawdown and could also commit to removing by the end of 2012 the remainder of the 30,000 extra "surge" troops he ordered deployed 18 months ago, according to a congressional source and and U.S. official familiar with the deliberations.
The president made his final decision on Tuesday on the scale and pace of a U.S. troop pullback in Afghanistan and will outline his plan in a televised address from the White House at 8 p.m. EDT (midnight GMT) on Wednesday.
Obama's announcement comes amid growing calls from an anxious Congress for an endgame in Afghanistan and appeals from the military not to tie its hands against a Taliban-led insurgency.
He has sought to balance arguments from Defense Secretary Robert Gates and military leaders for a slow drawdown of the 100,000 U.S. troops in Afghanistan against White House advisers advocating an accelerated pullout now that Osama bin Laden is dead and the 2012 re-election campaign is approaching.
But there were doubts whether Obama's decision would reconcile these conflicting pressures or satisfy any of the major players.
"He has been working through his decision over the course of the last several weeks and finalized that decision today," White House spokesman Jay Carney said on Tuesday.
While Carney declined to provide details of Obama's plan, he said it was in line with NATO's goal of turning over the lead for security across the country to Afghan forces by 2014.
His decision could have broad implications -- not only winding down U.S. involvement in Afghanistan but for the NATO alliance's commitment there and Washington's troubled relationship with neighboring Pakistan.
Obama intends to order the departure of roughly 5,000 surge troops, equivalent to an army brigade, starting next month and up to an equal number more by year-end, with the final number determined by conditions on the ground, the sources said.
He could also offer a blueprint for removing what remains of the 30,000-strong surge contingent by the end of 2012, which would give commanders the firepower they say they need for this fighting season and the next one, the sources said.
But the congressional source said that Obama might give the Pentagon some flexibility by stating that the remaining surge troops would leave at "a pace to be decided by the military."
Obama's decision comes at a critical juncture as lawmakers from both parties are anxious to curtail a military mission that is costing the United States $110 billion a year at a time of tight budgets and high unemployment at home.
A Pew Research poll released on Tuesday found a record 56 percent of Americans now favor bringing all U.S. forces home from Afghanistan as quickly as possible. [ID:nN1E75K1R4]
The killing of bin Laden in a U.S. raid last month has helped buttress the argument inside and outside the White House that there has been enough progress against al Qaeda to justify scaling back the war effort faster than expected.
Pentagon officials have voiced concern a rapid withdrawal would endanger gains against the Taliban while Obama advisers, including Vice President Joe Biden, are said to have pressed for a drawdown large enough to placate his Democratic Party's anti-war wing as well as a growing number of Republicans.
Obama had been reviewing a range of options presented by General David Petraeus, his top commander in Afghanistan.
Among the ideas under consideration was to set a timetable of up to 18 months to pull out all of the 30,000 extra troops he sent to Afghanistan, following a deep review of U.S. war strategy in late 2009, to break the momentum of the Taliban.
Obama has only said the initial withdrawal will be "significant."
As reports circulated about Obama's speech, Senate Armed Services Committee Chairman Carl Levin reiterated that the time was ripe to bring 15,000 troops home by the end of the year.
Another top Democrat, John Kerry, chairman of the Senate Foreign Relations Committee, said Obama's drawdowm decision should reflect the "level of progress" in the war effort.
Almost a decade after the Sept. 11, 2001, attacks that triggered the war, the Taliban has come under intense allied pressure in strategic areas of southern Afghanistan. But insurgents have fanned out and violence has surged along the Pakistan border.
The United States and other Western countries have poured billions of dollars of aid into Afghanistan, but with mixed results. Corruption remains rampant, and President Hamid Karzai's increasingly strident criticism of coalition forces has escalated tensions with Washington. (Additional reporting by Missy Ryan and Alister Bull; Editing by Cynthia Osterman)