Pakistan plans to fence up most of the 2,500 km (1,500 mile) frontier despite Kabul's protests that the barrier would divide families and friends along the Pashtun tribal belt straddling the colonial-era Durand Line drawn up by the British in 1893.
Pakistan's military estimates that it will need about 56 billion rupees ($532 million) for the project, while there are also plans to build 750 border forts and employ high-tech surveillance systems to prevent terrorists crossing.
In the rolling hills of the Angoor Adda village in South Waziristan, part of Pakistan's restive Federally Administered Tribal Areas (FATA), three rolls of barbed wire are sandwiched in the six-foot gap between the chain-link fences.
"(The fence) is a paradigm change. It is an epoch shift in the border control management," said a Pakistani army officer in command of South Waziristan during a presentation to foreign media on Wednesday.
"There will not be an inch of international border (in South Waziristan) which shall not remain under our observation."
Pakistan's military has so far fenced off about 43 km of the frontier, starting with the most violence-prone areas in FATA, and is expected to recruit tens of thousands of new troops to man the border. It is not clear how long it will take to fence the entire boundary.
But Pakistan's plans have also drawn criticism from across the border.
Gulab Mangal, governor of the eastern Afghan province of Nangarhar, told Reuters the wall will create "more hatred and resentment" between two neighbours and will do neither country any good.
"The fence will definitely create a lot of trouble for the people along the border on both sides but no wall or fence can separate these tribes," he said.
"I urge the tribes to stand against this action."
Pakistan has blamed Pakistani Taliban terrorists it says are based on Afghan soil for a spate of attacks at home over the past year, urging Kabul to eradicate "sanctuaries" for terrorists.
Afghanistan, in turn, accuses Islamabad of sheltering the leadership of the Afghan Taliban terrorists who are battling the Western-backed government in Kabul.
Both countries deny aiding terrorists, but relations between the two have soured in recent years. In May, the tension rose when 10 people were killed in two border villages in Baluchistan region.
The clashes occurred in so-called "divided villages", where the Durand Line goes through the heart of the community, and where residents are now bracing for the fence to split their villages in two.
Pakistan's previous attempts to build a fence failed about a decade ago and many doubt whether its possible to secure such a lengthy border.
But Pakistani army officials are undeterred by the scepticism and insist they will finish the job as the country's security rests on this fence.
"By the time we are done, inshallah, we will be very sure of one thing: that nobody can cross this place," said the Pakistani officer in charge of South Waziristan.