WASHINGTON — The Obama administration is considering the resumption of nonlethal military aid to Syria’s moderate opposition, senior administration officials said on Thursday, even if some of it ends up going to the Islamist groups that are allied with the moderates.

The United States suspended the shipments last month after warehouses of equipment were seized by the Islamic Front, a coalition of Islamist fighters that broke with the American-backed Free Syrian Army and has become an increasingly vital force in the nearly three-year-old uprising against President Bashar al-Assad.

But as a result of the rapidly shifting alliances within Syria’s fractured opposition, some of the Islamists fought alongside the Free Syrian Army in a battle against a major rebel group affiliated with Al Qaeda, the Islamic State of Iraq and Syria.

That has eased American qualms about resuming the aid, the officials said.

Restoring the aid, they said, would send a message of American support at a time when opposition groups are threatening to boycott a Jan. 22 peace conference out of concern that it will only serve to tighten Mr. Assad’s grip on power and discredit them at home.