BAGRAM, Afghanistan — A top American general said Sunday that attacks along the Afghan-Pakistan border have dropped more than 40 percent since July and the U.S. and its allies are making progress in the fight against the Taliban.

Brig. Gen. Joseph Votel said the decrease in insurgent activity along the border could be attributed to the onset of winter, a rise in insurgent attacks in Pakistan and an increase in communication and coordination among NATO, Afghan and Pakistani forces.

Recent media and analysts' reports have said the international mission is not succeeding and Afghanistan is becoming increasingly unstable. This year has been the deadliest since the 2001 U.S.-led invasion, with more than 6,300 people killed in the violence, mostly militants, according to an Associated Press count based on official figures.

The country has also seen a record number of suicide bomb attacks — more than 140 — this year.

But Votel, the deputy commanding general of U.S. troops in Afghanistan, said Sunday that the international mission is making progress.

"I don't agree that we're moving in a negative direction," Votel told journalists at Bagram, the main U.S. base.

"I think we are making progress. This is a long-term proposition and there is a long way to go in security and development and other aspects here, but we are making progress and moving forward," he said.

Votel said that, by U.S. measurements, security has increased in 25 districts that American forces oversee in eastern Afghanistan, governance has improved in 12 and development work has improved in 27. There is a total of 159 districts in the eastern region of Afghanistan where U.S. troops primarily operate.

He said the U.S. military has killed or captured more than 50 "significant" insurgent leaders this year, action that has created a "void on the battlefield." He said despite those losses, insurgents have shown some improvements in their effectiveness.

In a new assessment published by the Center for Strategic and International Studies last week, analyst Julianne Smith cautioned that the situation in Afghanistan is growing increasingly unstable, saying the country is headed in the wrong direction and that a complete overhaul of NATO strategy was needed.