KABUL - The Chairman of the US Joint Chiefs of Staff Gen. Martin Dempsey pays an unannounced visit to Afghanistan, local media reported Monday.

"The Chairman of the US Joint Chiefs of Staff Gen. Martin Dempsey arrived in Bagram air base in north of Afghan capital of Kabul in the wee hours Monday," local TV channel Tolo reported in its news bulletin. ?

Dempsey will meet with the NATO and Afghan military officials including the top US and NATO commander in the county, Gen. John R. Allen, with the so-called "green-on-blue" or insider attacks at the top of the agenda, according to the report. ?

His trip came one day after a man wearing an Afghan National Police uniform opened fire against US forces, killing one US soldier with the coalition in southern Kandahar province, the latest in the series of insider attacks when Afghan army, police or gunmen in their uniform turned their weapons against coalition forces.

Taliban insurgent fighting Afghan and NATO forces regularly claimed responsibly for the green-on-blue attacks.

Up to 29 such attacks took place so far this year, leaving at least 40 US and NATO soldiers dead across the insurgency-hit country.