KABUL, Afghanistan – The NATO-led command stressed Sunday that military operations to secure vast areas of Afghanistan will not be delayed by the ouster of its top commander and mounting casualties.

To reinforce the message, NATO announced that more than 600 Afghan and international troops were battling al-Qaida and Taliban forces Sunday in the eastern province of Kunar, which borders Pakistan. Three members of the allied force were killed in the fighting, including two Americans, a military statement said.

NATO and U.S. forces are awaiting the arrival of new commander Gen. David Petraeus, who is taking over from Gen. Stanley McChrystal. He was dismissed by President Obama after he and his aides were quoted in “Rolling Stone” magazine making disparaging remarks about top Obama officials.

There has been concern that the leadership shake-up will further slow a push into the volatile south that has already been delayed by months in some areas.

But NATO spokesman Brig. Gen. Josef Blotz told reporters in Kabul that the worries are unwarranted and the military is not pausing because of the changes. He added that Petraeus was expected in Kabul in the next seven to 10 days.

The top American military officer, Adm. Mike Mullen, flew to Afghanistan on Saturday to assure President Hamid Karzai that Petraeus will pursue the policies of his predecessor, including efforts to reduce civilian casualties.