WASHINGTON (AP) — A senior administration official says President Barack Obama is considering sending lethal assistance to Ukraine's besieged military.

The official says Obama continues to have concerns about taking that step, including the risks of starting a proxy war with Russia and the Ukrainian military's capacity for using U.S.-supplied weaponry. The official says Obama is also concerned that no amount of arming the Ukrainians would put them on par with Russia's military.

Still, the official says the White House is willing to take a fresh look at the matter given the recent escalation of violence between Ukraine and pro-Russian separatists.

The New York Times first reported the new Obama administration deliberations. The official confirmed the discussions on the condition of anonymity because this person wasn't authorized to discuss the internal deliberations publicly.