BAGHDAD (AP) — After intense U.S. assaults, al-Qaida may be considering shifting focus to its original home base in Afghanistan, where American casualties are running higher than in Iraq, the top U.S. commander in Iraq said Saturday.

‘‘We do think that there is some assessment ongoing as to the continued viability of al-Qaida’s fight in Iraq,’’ Gen. David Petraeus told The Associated Press in an interview at his office at the U.S. Embassy.

Whatever the result, Petraeus said no one should expect al-Qaida to give up entirely in Iraq.

‘‘They’re not going to abandon Iraq. They’re not going to write it off. None of that,’’ he said. ‘‘But what they certainly may do is start to provide some of those resources that would have come to Iraq to Pakistan, possibly Afghanistan.’’

He said there are signs that foreign fighters recruited by al-Qaida to do battle in Iraq are being diverted to the largely ungoverned areas in Pakistan from which the fighters can cross into Afghanistan. U.S. officials have pressed Pakistan for more than a year to halt the cross-border infiltration. It remains a major worry not only for the war in Afghanistan but also for Pakistan’s stability.