WASHINGTON, May 4 (Xinhua) -- The U.S. military's focus needs to shift immediately from Iraq to Afghanistan, given increasing security concerns there, the country's top military officer said here on Monday.

    "We remain committed to the mission we've been given in Iraq --make no mistake. ... But Afghanistan has been an economy of force operation for far too long," Michael Mullen, chairman of the Joint Chiefs of Staff, told a Pentagon news conference.

    He noted that while U.S. President Barack Obama's decision to increase troop levels in Afghanistan "provides commanders (with) more manpower and more resources," "we need a commensurate commitment from a civilian side."

    The top officer said he is "gravely concerned" about Taliban and al-Qaida gains across much of southern Afghanistan and in Pakistan.

    Mullen's remarks came days after the release of a State Department report indicating a dramatic spike recently in terrorist attacks in Afghanistan and neighboring Pakistan.

    White House press secretary Robert Gibbs said Obama has similar concern.

    The president, who is meeting with the presidents of Afghanistan and Pakistan later this week, wants an "understanding that not just the United States faces security concerns, but each individual government has security concerns about extremists in the area," Gibbs said at Monday's White House press briefing.