Report: US mulls clandestine raids into Pakistan

Gen. John Allen, the top U.S. commander in Afghanistan, along with several high-level U.S. intelligence and special-operations leaders, were briefed on the plan, according to reports by the Associated Press. 

Border clashes between coalition forces and terror groups like the Pakistani-based Haqqani Network have produced some of the heaviest fighting since the Obama administration surged more than 20,000 U.S. troops into the southern part of the country in 2009.

Islamabad's unwillingness to adequately seal off the border and root out terror groups seeking asylum inside Pakistan has continued to be a roadblock in increasingly strained relations between Washington and Islamabad.

Allen met with Pakistani army chief Gen. Ashfaq Kayani on Wednesday to find some common ground on the border issue. 

However, a number of top Pentagon officials including Defense Secretary Leon Panetta have accused Islamabad of providing safe haven and support to Haqqani fighters and other militant Islamic groups inside its borders.

Growing frustration inside the Pentagon and on the ground in Afghanistan over the border incursions has pushed U.S. military leaders to consider executing their own raids into Pakistan territory. However, Allen and others have expressed concern that U.S-led raids into Pakistan would shatter the already fragile alliance between the two countries. 

Allen's spokesman, Navy Cmdr. Brook DeWalt, said on Wednesday the four-star general "has not and does not intend to push for a cross-border operation," according to the AP. 

That said, the Pentagon and CIA have ramped up aerial drone strikes against suspected terror targets inside Pakistan's borders. American drones reportedly killed four militants during an airstrike in North Waziristan on Tuesday.

Islamabad has chastised the attacks as an outright challenge to Pakistan's sovereignty and demanded an end to all drone strikes inside its borders.