Islamabad, Jun 19 (IANS): Pakistan wants an "appropriate" apology from the US over the NATO air strike last year that killed its two dozen soldiers, the country's ambassador to Washington Sherry Rehman has said.

Rehman said the apology over the Salala border post incident was important to help move the bilateral relationship forward, Dawn News reported Tuesday.

She said the two countries are in a "critical phase" of negotiating new terms of engagement and narrowing down their differences.

Rehman said the supply routes to Afghanistan through Pakistan would "remain closed pending a US apology".

"The debate on the matter has been wrongly cast as a price haggle or price gouging in the US media. This is not the case," she said.

On drone strikes in Pakistan's northwest tribal region, the envoy said: "We want our American friends to respect our sovereignty and territorial integrity. This means no drone attacks and no incursions into Pakistani territory."

Rehman said she was not highlighting Pakistan's sacrifices in the war on terror as part of some "victim narrative" but was reminding the world of the key contribution her country has made over the last several years.

"We have helped arrest or neutralise nearly 250 Al Qaeda members, provided the US free use of our highways to transport supplies to Afghanistan. We have lost more than 37,000 Pakistanis to terrorism. Over 5,000 security and law enforcement personnel have laid down their lives fighting terrorism," she said.

"I hope we can narrow our differences and move expeditiously forward. In the context of our region, Pakistan and the US working individually are a lot less effective than the sum of the two working together."