WASHINGTON: A US envoy on a mission to discuss post-war Afghanistan will head on a previously unscheduled trip to New Delhi after Pakistan refused his visit, officials said Wednesday.

US officials said Pakistan informed them that it did not want to receive special envoy Marc Grossman until Islamabad completes an ongoing review of relations with Washington, which have sunk to rock-bottom in recent months.

The State Department said Grossman would head Friday to India.

State Department spokeswoman Victoria Nuland said that the United States was not trying to send any message to Pakistan through Grossman's trip to India and reiterated that he would have liked to visit.

"We made clear that we would welcome a stop by Ambassador Grossman in Islamabad on this trip," she told reporters. "The Pakistanis are looking hard internally at our relationship. They asked us to give them time to do that, so he will not be going there on this trip," she said.

Nuland said that the United States welcomed efforts by India, which has given more than $2 billion in aid to Afghanistan and plans to take a larger role training Afghan troops and security forces.

"We believe that India has a role to play in supporting a democratic, prosperous future for Afghanistan," she said.

After New Delhi, Grossman heads to Afghanistan on Saturday for talks with Karzai. He is also visiting Qatar, Saudi Arabia, Turkey and the United Arab Emirates on his nearly two-week trip. (AFP)