The Obama US administration will seek to block a controversial bill that describes as genocide the 1915 killing of Armenians by Turks.
The US Congress Committee had narrowly approved the resolution on March 4, by 23 to 22 votes. This had paved the way for a possible vote by the House, something that the administration would seek to prevent.
Turkey reacted strongly to the vote, recalling its Ambassador from Washignton, and threatening further diplomatic protest. Turkish citizens took to the streets to voice their anger at the decision.
"We are against this decision. Now we believe that the US Congress will not take any decision on this subject," Hillary Clinton, the US Secretary of State, stated on Friday.
During his campaign for the 2008 election, Barack Obama had promised to brand the mass killings genocide.
However, Clinton has acknowledged his administration's change of opinion on the issue, saying that circumstances had "changed in very significant ways".
Turkey is a major partner in US efforts to stabilize Afghanistan and Iraq, and lies on a key route taking oil and natural gas to Western markets.
In October 2009, Turkey and Armenia signed a historic accord normalising relations between them after a century of hostility, but successive Turkish governments have refused to accept responsibility for any suggestion of genocide.