KABUL, AFGHANISTAN - Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, arrived Monday in Afghanistan for discussions on the progress of the war, including an intensified wave of insider attacks by Afghan forces on NATO service members, even as New Zealand became the latest coalition partner to announce an accelerated troop withdrawal.

The visit by Dempsey comes after a trust-eroding two-week stretch in which 10 U.S. service members were killed by Afghan security forces in violence designated as insider or "green-on-blue" attacks.

Dempsey met in Kabul with U.S. Gen. John Allen, the top commander in Afghanistan, and other senior coalition and Afghan officials, a NATO spokesman said. Dempsey received an update on the campaign, and the insider attacks were "certainly among the topics of discussion," one NATO official said.

Also Monday, President Obama said that he would be conferring with Afghan President Hamid Karzai about the attacks but was sticking with the current strategy of using U.S. troops to advise and mentor Afghan forces.

New Zealand announced it planned to withdraw its troop contingent from Afghanistan ahead of schedule, aiming for early 2013 rather than October of that year. It has about 140 soldiers in Afghanistan, mainly in Bamiyan Province. This month five of them were killed, but officials said that had no bearing on the withdrawal schedule.