WASHINGTON, June 24 US military chief Admiral Mike Mullen leaves Washington on Thursday evening for a visit to Afghanistan and Pakistan to explain the new change of command in Kabul to leaders of the region.

US official sources told Dawn that the admiral was already scheduled to visit Islamabad to attend a ceremony to mark the handing over of F-16 fighter jets to Pakistan.

US and Pakistani officials announced earlier this week that first four of these 18 F-16s would arrive at the Shahbaz Airbase in Jacobabad in the last week of June. The entire batch will be in Pakistan by the end of December. But officials in Washington said that Admiral Mullen, who is the chairman of the US Joint Chiefs of Staff, will also avail this opportunity to “assure Afghan and Pakistani leaders that the change in the US command in Kabul will not affect them”.

US President Barack Obama sacked his top commander in Afghanistan, Gen Stanley McChrystal, on Wednesday over insubordination, stressing that in a democracy institutions were stronger than individuals and chose Gen David Petraeus, the current chief of the US Central Command, to replace him.

Meanwhile, the US Senate Armed Services Committee will hold a confirmation hearing for Gen Petraeus on Tuesday as both Republicans and Democrats indicated they would approve his appointment. But the Republicans said they would use the hearing to sound the alarm over President Obama's July 2011 deadline to start withdrawing troops from Afghanistan.