The Pentagon is taking a close look at its war strategy in Afghanistan in the face of rising violence from an increasingly complex insurgency, Defense Secretary Robert Gates said. In Washington, a senior U.S. official said the State Department was conducting its own formal review expected to last several weeks, indicating a broader rethink by the Bush administration of its strategy in Afghanistan. Gates declined to say if a formal or informal review had been launched by the Pentagon but noted the United States had previously examined its strategy in Iraq, a review that resulted in major changes, including a boost in troop numbers. "We are taking a close look at it and I don't know whether the results of that will be a significant change in strategy or just some adjustments," Gates told reporters in London. "You have an overall approach, an overall strategy, but you adjust it continually based on the circumstances that you find," he said. "We did that in Iraq and we made a change in strategy in Iraq, and we are going to continue to look at the situation in Afghanistan," said Gates, who visited Afghanistan this week before flying to London for a meeting with NATO counterparts. The State Department review was being led by the department's policy planning staff and the South and Central Asian Affairs bureau that handles Afghanistan, the senior U.S. official said. A senior U.S. defense official said the Pentagon was looking at a broad range of elements in its Afghan strategy, including how the extra brigade would affect the mission. One question was whether U.S. forces should take on more combat missions, leaving NATO nations with more restrictions on use of their forces to concentrate on other tasks, said the official, briefing reporters on condition of anonymity.