The U.S. Defense Department announced Wednesday that most of the U.S. army troops now in Iraq and Afghanistan and other parts of the Middle East and East Africa will have their assignments extended from 12 months to 15 months, and that the longer tours of duty will apply to soldiers who deploy to the region for the foreseeable future. VOA's Al Pessin reports from the Pentagon the move is designed to enable the U.S. military to sustain the higher troop level in Iraq that President Bush ordered in January.

Defense Secretary Robert Gates announced the change in policy Wednesday, saying he hopes it will be temporary, but unable to say how long it will last.

"This policy, as a matter of prudent management, will provide us with the capacity to sustain the deployed force," said Robert Gates. "This approach also upholds our commitment to decide when to begin any drawdown of U.S. forces in Iraq solely based on conditions on the ground."

Secretary Gates said the change will enable the U.S. military to sustain the surge of more than 20,000 additional troops in Iraq for at least a year, but he said no decision has been made to maintain the higher troop level for that long.

"We are creating the capability to keep it in place," he said. "Whether it will be kept in place, depends entirely on the conditions on the ground."

Secretary Gates repeated his expectation that the surge will last "months, not years," but he also noted that the top U.S. commander in Iraq has said he will not be able to even begin to evaluate the impact of the surge until August.

The secretary and the top U.S. military officer, General Peter Pace, acknowledged that extending combat tours will put a further strain on the U.S. military. General Pace said steps are being taken to reduce the strain in the future, including a long-term expansion of the U.S. Army and Marine Corps. But he said for now, U.S. leaders have no choice but to ask more of the current troops and their families.

"Is it an additional strain to go from 12 months to 15 months? Of course it is," said General Pace. "Is it in combat and therefore even more difficult? Of course it is. The troops want to and deserve to know that their leaders are mindful of what we're asking them to do, mindful of the additional strain, working to make that less than it is."

The policy of the U.S. Defense Department is to provide active-duty soldiers two years at home for every year of deployment abroad. The wars in Iraq and Afghanistan, as well as other U.S. military commitments worldwide, have moved that to one year away and one year at home.

Secretary Gates said the decision to move to 15 months away and a year at home is designed in large part to ensure that all soldiers do get the full 12 months at home before their next deployment, and to provide predictability to the soldiers and their families. He said he hopes to get back to the original deployment schedule, but he could not say when that might happen.

The decision on longer deployments in Iraq, Afghanistan and some nearby areas only affects the Army, not the other U.S. military services, and only active-duty soldiers, not members of the Reserves or the National Guard. The vast majority of the U.S. troops in that region are active-duty members of the Army.