House sponsors of a resolution that would label the 1915 killing of Armenians a genocide have asked Speaker Nancy Pelosi to delay a vote on the measure because they feared it would fail.

Support for the resolution deteriorated this month, after Turkey recalled its U.S. ambassador in protest and several lawmakers said they feared it would cripple U.S.-Turkey relations.

"We believe that a large majority of our colleagues want to support a resolution recognizing the genocide on the House floor and they will do so, provided the timing is more favorable," the lawmakers told Pelosi in a letter on Wednesday.

The letter was signed by four primary sponsors of the resolution: California Democrats Adam Schiff, Anna Eshoo and Brad Sherman, and Frank Pallone, D-N.J.

The group said they would continue to work with leadership "to plan for consideration sometime later this year, or in 2008."