Heavy fighting began in August in Bajaur, described as a "centre of gravity" for militancy in the region, but two valleys still have to be cleared, Major General Tariq Khan said.
Victory in Bajaur will provide relief for U.S. and NATO forces hard-pressed by the insurgents across the border in eastern Afghanistan.
Tribal elders involved in talks with militants, said Faqir Mohammad, the main Taliban commander in Bajaur, could offer a ceasefire imminently.
During the interview at the Frontier Corp's headquarters in historic Balahisar Fort, in the northwestern city of Peshawar,, Khan received word that his forces had taken the strategically important village of Barchina.
"It means that Charmang is now in our hands," he said, referring to one of the remaining valleys leading to eastern Afghanistan.
He foresaw the offensive continuing until mid-March, but added; "These are not deadlines, they're judgements".
He said he was forced to carry out an offensive in neighbouring Mohmand tribal area after militants launched a major attack on his forces there last month.
Khan said the attack failed but prodded him into action, and military convoys now pass safely through Mohmand.
Khan was switched to Bajaur and appointed commander of the paramilitary Frontier Corps (FC) weeks after the fighting began to hot up in the most northeasterly of Pakistan's seven semi-autonomous tribal regions.
The Frontier Corps is recruited from the ethnic Pashtun tribes of the region, and they have led the fighting in Bajaur because their presence is more acceptable to the fiercely independent tribesmen.
The government helped mobilise tribal armies, known as lashkars, to help combat the militants in Bajaur.
HAMPERED BY TENSIONS
Thick-set and bespectacled, Khan is Pashtun, and has a strong understanding of the people and tribal dynamics.
His appointment was welcomed by senior U.S. military officials, impressed by Khan's success in bottling up militants led by Pakistani Taliban leader Baitullah Mehsud in the South Waziristan tribal region.
Pakistani military officials said in October that more than 1,500 militants, including Chechans, Uzbeks and Arabs had been killed in battles in Bajaur, though there had been no independent verification of the claims.
Khan said his forces had eliminated several middle-tier militant leaders, but he regretted not having wound up the offensive sooner.
"We should have finished these operations much earlier."
The delay in completing the Bajaur campaign was a result a particularly severe winter and tensions with India in the aftermath of an attack on the Indian city of Mumbai by Pakistani militants last November.
He said "two battalions" were redeployed because of the weather and concern on the eastern border with India.
The New York Times reported on Sunday that 70 American military advisers were in Pakistan training the army and paramilitary forces, but Khan denied this, complaining at the inadequacy of U.S. support.
"Are Americans giving us any lethal assistance? Do we get any rocket launchers or bombs or aircraft (from them)? We are getting nothing actually," he said.
"What we are getting are bullet-proof jackets, helmets, water bottles ... medication, surveillance equipment and communication equipment," he said.
The United States had given close to $44 million worth of equipment to the Frontier Corps till last year, but has given billions of dollars in aid to help Pakistan fight militancy since it became an ally in 2001.