A top Hamas official said the Palestinian group is losing faith in the United States’ ability to mediate a ceasefire in Gaza ahead of a new round of talks scheduled for this week amid mounting pressure to bring an end to the 10-month-old war on the enclave. Osama Hamdan told The Associated Press in an interview Tuesday that Hamas will only participate if the talks focus on implementing a proposal detailed by U.S. President Joe Biden in May and endorsed internationally. The U.S. referred to it as an Israeli proposal and Hamas agreed to it in principle, but Israel said Biden’s speech was not ent…