Maj Gen Nauman Zakaria, the Pakistan commander for the South Waziristan region, told reporters during a visit to the border on Wednesday that the fencing and surveillance technology would prevent attacks on both sides of the border.
Pakistan began construction of the fencing earlier this year.
The army said that newly installed fence and guard posts along the Pak-Afghan border will help prevent militant attacks.
United States President Donald Trump has recently reiterated longstanding accusations that Pakistan turns a blind eye to militant groups that launch attacks in Afghanistan from within its territory, allegations always denied by Islamabad.
Afghanistan has levelled similar accusations but has also objected to the building of the border fence. The stepped-up fortifications have angered Kabul, which does not recognise the frontier as an international border.