The US National Security Adviser, Tom Donilon has said that though in ongoing circumstances ties with Pakistan have become difficult but also essential as well.

While delivering a public speech on the US policy towards Asia at the Asia Society, Tom Donilon said that crisis no longer looms over US relationship with Pakistan as over the past year, both the countries have worked hard to overcome the period of strain in their ties.

"We have had, as you might imagine, as has been clear, some difficult issues, but I do think we re at a point here where we don t have a crisis hanging over the relationship. We continue to work intensively with the Pakistanis on the kinds of issues, and we’ll continue to do so", head added.

The US National Security Adviser said that they have had with Pakistan a very important partnership in the counter-terrorism area. And indeed the Pakistanis have suffered thousands of casualties in the battle against extremism.

He said Pakistan has been an important partner of the US in its efforts against the most extreme elements.

“We have had difficult issues between the US and Pakistan. And indeed we had a long period of time when it felt like our relationship always had a crisis. We obviously had a difficult time after we executed successfully the Abbottabad raid against Osama bin Laden in May 2011 and there was a reaction.”

The US national security advisor also referred to Islamabad closing the crucial ground lines of communications to Afghanistan after the "terrible" cross border incident in November 2011 in which two dozen Pakistani soldiers were killed.

"We have worked through these issues. I think, actually are now at a point where we re having broader conversations without the overlay of some crisis, and talking about kind of more fundamental strategic interests that we have in common," he said.

The national security adviser said the US and Pakistan have in common a stable Afghanistan at the end of this process, and the two countries are working together on that.

"We both have in common the fight against extremist elements, and we continue to work on that," he said.

Referring to the upcoming general elections in Pakistan, Donilon termed it as a milestone towards strengthening of the democracy in the country, and said the US will be "watching that."