The US has evidence linking the Pakistan government to the Haqqani network, which was behind this week's attack on the American Embassy in Kabul, US Ambassador to Pakistan Cameron Munter has said.

 A "lot of work" is needed to put Pakistan-US ties back on track and Islamabad must sever its links with militant groups like the Haqqani network, Munter said in a wide-ranging interview with Radio Pakistan.

"Let me tell you that the attack that took place in Kabul a few days ago, that was the work of the Haqqani network. And the facts, that we have said in the past, that there are problems, there is evidence linking the Haqqani network to the Pakistan government," he said in response to a question about the current state of bilateral ties.

He did not give details about the evidence.

"This is something that must stop. We have to make sure that we work together to fight terrorism.

"We have to make sure that the efforts that we are making to build the ties between our intelligence services bring about results," he said.

The US has to talk with the Pakistan government "very openly and clearly about how we can make sure" that attacks like the one in Kabul do not happen in future, Munter said.

Efforts are being made to recognise the "common enemy" of the US and Pakistan who attack people of both countries and their allies, the envoy noted.

"We have to fight these people. We cannot let events like that happened in Kabul to take place," he said.

Munter's remarks came close on the heels of a warning from Defense Secretary Leon Panetta that the US would retaliate against attacks on its forces in Afghanistan by Pakistan-based militants.