WASHINGTON (Reuters) -- Pakistan has shifted 100,000 of its troops from its Indian frontier to spearhead an unprecedented crackdown on militants along the Afghan border, but the offensives are unlikely to have an immediate impact on the U.S.-led war in Afghanistan, the Pentagon said.
In a report to Congress released on April 28, the Pentagon estimated that about 140,000 Pakistani troops were taking part in offensives against militants in the semi-autonomous tribal regions, known as the Federally Administered Tribal Areas, or FATA, and the Northwest Frontier Province, near Afghanistan.
The Pentagon, which had long pressed the Pakistanis to take on Taliban and Al-Qaeda leaders on their territory, said the recent military deployments were the biggest in the country's history on the western border.
To carry it out, Pakistan has shifted more than 100,000 troops from the eastern border with India, according to the report.
"This unprecedented deployment and thinning of the lines against India indicates that Islamabad has acknowledged its domestic insurgent threat," the Pentagon said.
The Pentagon issued the report one day before the prime ministers of India and Pakistan are due to hold their first meeting in nine months. Washington has sought to improve frayed ties between the South Asian rivals, who have fought three wars since their independence from Britain in 1947.
In the report, the Pentagon said Pakistani military operations in the FATA and the Waziristans have had an impact across the border, placing a "high degree of pressure on enemy forces and reduced insurgent safe haven" in eastern Afghanistan.
Recent arrests by Pakistan of Afghan Taliban leaders, including the group's No. 2, Mullah Abdul Ghani Baradar, have "increased insurgent leaders' concern over the security of their safe havens" and created "financial and logistical" problems, it said.
A senior U.S. defense official said the arrests in Pakistan had produced "a lot of concerned chatter" among Taliban sympathizers in Afghanistan, but added, "I've not seen anything to indicate...that there is a leadership crisis in the Taliban."
The Pentagon said Islamabad's crackdown had thus far "focused almost exclusively on internal threats."
"While this evolving approach is unlikely to have significant impact on the Afghan insurgency in the short term, it offers opportunities in coming months to have a greater impact on the conflict in Afghanistan depending on how PAKMIL (Pakistani military) operations evolve," the report said.