WASHINGTON (Reuters) -Israel and Hamas may be able to reach a Gaza ceasefire and hostage-release deal within one or two weeks but such an agreement is not likely to be secured in just a day's time, a senior Israeli official said on Wednesday. Speaking during Israeli Prime Minister Benjamin Netanyahu's visit to Washington, the official said that if the two sides agree to a proposed 60-day ceasefire, Israel would use that time to offer a permanent ceasefire that would require the Palestinian militant group to disarm. If Hamas refuses, "we'll proceed" with military operations in Gaza, the official said on condition of anonymity.