* Vote to speed up Afghan withdrawal falls just shy
* House passes $690 billion defense authorization
* Measure faces White House veto threat
(Adds Hoyer criticism of bill, 12th para)
WASHINGTON, May 26 (Reuters) - House lawmakers sent a clear warning to President Barack Obama about growing exhaustion over the war in Afghanistan on Thursday as they passed a defense policy bill authorizing $690 billion in military spending for the 2012 fiscal year.
Members of the House of Representatives made two attempts to force a change in Obama's Afghan war strategy, falling just a few votes shy on one measure that would have required him to begin planning for a stepped-up withdrawal. A vote to bar U.S. troops on the ground in Libya passed nearly unanimously.
The votes came as the Republican-led House debated and passed the National Defense Authorization Act, 322-96, approving a $553 billion Pentagon base budget and $119 billion for overseas contingency operations, mainly the wars in Afghanistan and Iraq. The remaining $18 billion is for military-related nuclear activity at the Department of Energy.
A Senate panel was expected to start work on the bill next month. Both chambers must agree on the same legislation before it goes to President Barack Obama for his signature into law.
Although the bill authorizes expenditures, it is primarily a means for Congress to set out defense policy. Actual spending levels are established by appropriations bills.
Among the policies approved as part of the bill were:
-- A provision requiring that "foreign terrorists" detained by the United States be considered enemy combatants and tried in military tribunals rather than the civilian court system.
-- A move to keep alive an alternate engine being developed by General Electric Co (GE.N). and Rolls-Royce Group Plc (RR.L) for the F-35 Joint Strike Fighter, which was eliminated by the Pentagon in a cost-cutting move.
-- Conditions that would link implementation of the New START nuclear arms treaty with Russia to completion of the next generation of U.S. nuclear production facilities, which will not be finished until the mid-2020s.
-- A proposal to eliminate the U.S. Institute of Peace, a congressionally funded institution that works to stabilize fragile states and end conflicts like the one in Afghanistan.
The bill has drawn a veto threat from the White House because of its provisions on the New START treaty, the jet fighter engine and handling of terrorism suspects.
House Democratic Whip Steny Hoyer criticized language in the bill that he said would dramatically expand the president's powers to use military force and attempt to reopen the repeal of a ban on gay men and women serving openly in the military. Still, Hoyer voted in favor of the measure.
'NATION-BUILDING' NEEDED AT HOME
Much of the debate on the bill dealt with the conflicts in Afghanistan, Iraq and Libya as lawmakers voiced frustration over the lack of an end in sight after 10 years of war.
"The American people have grown weary of open-ended military conflicts that place our troops in harm's way and add billions to our national debt," Democratic Representative John Conyers said in debate on his proposal to ensure no defense funds could be used to deploy ground troops in Libya.
Hoyer said that after backing the Afghanistan war for 10 years, he now supports requiring Obama to begin planning for withdrawal.
"The death of Osama bin Laden was a landmark moment," he said. "The struggle has not ended with bin Laden's death, but his death is a moment for reflection on that struggle and how we can best equip ourselves to win it."
Representative Jim McGovern, who sponsored the measure, warned that Obama was likely to start his promised drawdown in Afghanistan in July with a token of perhaps 5,000 troops.
"We need to safeguard our national security ... but many of our greatest problems aren't halfway around the world, they're halfway down the block. And rather than nation-building in Afghanistan, we need to do some more nation-building right here in the United States," he said.
His proposal, which would have required a withdrawal plan and stepped-up efforts for a political solution, failed on a 204-215 vote. Twenty-six Republicans joined 178 Democrats in backing it. Last summer, a similar measure got 162 votes.
A separate proposal by Republican Representative Jason Chaffetz would have required U.S. ground troops to withdraw from Afghanistan, aside from those involved in small, targeted counter-terrorism operations. It failed on a vote of 123-294.
(Editing by Cynthia Osterman)