"We certainly look forward to working together with her as we continue to build a strong co-operative relationship between the two countries," State Department Deputy Spokesman Mark Toner said at the daily briefing.

He was asked to comment on Islamabad's announcement that Sherry Rehman, a parliamentarian and known journalist will replace Husain Haqqani as the country's ambassador to the United States.

Toner though said the State Department has not yet received a formal notification in this regard.

He said the US government communicates with the Pakistani government through multiple channels and ambassador in Washington is one of the important channels.

The spokesman acknowledged former ambassador Haqqani's strong support for US-Pakistan relations but also conceded that the US has relations with governments.