PESHAWAR, Pakistan — The Pakistani army declared on Wednesday that its four-month-long offensive against insurgents in a restive tribal region bordering Afghanistan has been a success, saying that the troops have so far killed 1,100 militants.

But the military also accused neighboring Afghanistan of not providing "enough support" to the Pakistani operation in North Waziristan, and allegedly failing to take action against militants who have fled across the frontier to hide among the Afghans.

The army spokesman, Maj. Gen. Asim Saleem Bajwa, did not substantiate those claims but such accusations from Islamabad are common amid tense relations between the two neighbors. Afghan officials did not immediately comment on the remarks.

Bajwa told reporters in the northwestern city of Peshawar that the offensive in North Waziristan, which was launched in June, was going according to plan and that its impact is being felt across Pakistan, with a decrease in "terrorist attacks, extortion and kidnappings."

"Most areas and roads in North Waziristan have been cleared and reconstruction is underway," he said, adding it was still unclear when the operation would be finished. He said troops seized 132.5 metric tons (146 tons) of explosives, thousands of weapons and a large cache of ammunition.

The tribal region was considered a sanctuary for local and foreign militant groups until the military launched its offensive following a deadly militant attack on the country's busiest airport in Karachi.

Bajwa said the results of the operation would have been even better if Afghan authorities had provided assistance.

He said Pakistan informed Afghan authorities that militants and their leadership fled across the border and were camped out in Afghan territory from where they were launching attacks against Pakistani troops.

"Afghan authorities have not taken any action," he said. "They have not killed or arrested and handed over any militants to Pakistan."