NEW DELHI (AFP) - The United States said Thursday that it expected the Taleban to continue to mount attacks in Afghanistan even as the rebels hold peace talks from their new office in Qatar.

Taleban gunmen and bombers using fake Nato identification attacked an entrance to the Afghan presidential palace and a nearby building known to house a CIA base on Tuesday, leaving three security guards dead.

"Frankly I anticipate that Taliban will continue to try to negotiate from a position of strength," US special envoy to Afghanistan and Pakistan, James Dobbins, told reporters in New Delhi.

"The Taleban will want to continue to put pressure on, to make it look like the United States is leaving as a result of that pressure rather than a result of its success," he added.

Mr Dobbins, who is on the last stop of a tour through South Asia, said he had briefed his Indian counterparts about the uncertain peace process, which has caused concern in New Delhi.

"They clearly had anxieties, anxieties that we all have. Nobody knows how this is going to progress," Mr Dobbins said.

India, which has spent more than US$2 billion (S$ 2.7 billion) of aid in Afghanistan, fears any return of the influence of the Taleban, hardline Islamists that are aligned with Pakistan.

India and Pakistan are locked in a fight for influence in Afghanistan, but Mr Dobbins saw the prospect of improved relations between the neighbours which have fought three wars since independence.

In foreign policy matters, Pakistan's new Prime Minister Nawaz Sharif has made improving relations with India his "top priority," said Mr Dobbins after his talks in Islamabad on Tuesday.

"Any improvement in India-Pakistan ties will almost automatically improve Afghanistan's situation," he added.

The Taleban opened an office in Qatar last Tuesday which was immediately mired in controversy after they used a flag and plaque which styled them as a government in exile. The United States has pressed for a political solution to end the violence in Afghanistan ahead of the US-led Nato combat mission finishing in 2014.