Washington, Aug 17 (IANS): Top US officials admit Washington has "no choice" but to maintain close relations with Pakistan despite government links with militant groups. including the Lashkar-e-Taiba (LeT) blamed for the Nov 2008 Mumbai terror attacks.

Pakistan has "relationships" with the Haqqani network - militants based in western Pakistan who conduct cross-border attacks on US forces in Afghanistan, and with LeT, both listed by the US as terrorist organizations, Defence Secretary Leon Panetta said Tuesday.

"There's a relationship with LeT and -- you know, this is a group that goes into India and threatens attacks there. It has conducted attacks there," he said at a public forum with Secretary of State Hillary Clinton at Washington's National Defence University.

"And yet there is no choice but to maintain a relationship with Pakistan. Why? Because we're fighting a war there," Panetta, who took over as defence secretary in June after two years of heading the CIA, said.

Clinton said the Obama administration considers relations with Pakistan to be of "paramount importance."

She said there have been "challenges" in bilateral ties for decades with valid complaints on both sides, and that she credits the Islamabad government with lately recognizing its shared interest with Washington in confronting terrorism.

"I was very pleased when the Pakistanis moved into [the] Swat [Valley] and cleaned out a lot of what had become a kind of Pakistani Taliban stronghold," said Clinton. "And then they began to take some troops off their border with India, to put more resources into the fight against the Pakistani Taliban.

"Now, as Leon [Panetta] says, we have some other targets that we discuss with them - the Haqqanis, for example. And yet it's been a relatively short period of time, two-and-a-half years, when they have begun to reorient themselves militarily against what is, in our view, an internal threat to them."

Later at the State Department asked why US was not putting Pakistan among state sponsors of terrorism despite its relationship with two banned terror organizations, spokesperson Victoria Nuland said: "I think Secretary Panetta spoke to our concern about how these two organizations operate.

"Any relationship that they may have with Pakistan, which is a subject that we talk about with Pakistan, which is a different issue than a state being a sponsor of terrorism itself."