WASHINGTON: The US has not seen Pakistan taking sustained and decisive actions required to bring the Taliban to the negotiating table, a top Trump administration official told lawmakers who demanded suspension of all American aid to Pakistan

Principal Deputy Assistant Secretary of State for South and Central Asia Alice Wells during a Congressional hearing on Afghanistan told the lawmakers that Pakistan has a particularly crucial role to play in the war-torn country as without its support it will challenging to achieve the US' objectives under the South Asia strategy.

"While we've seen some positive steps, our assessment has been that we have not seen the sustained and decisive actions that are really required to ensure that the Taliban take this peace process seriously," she said.

"We would like to see Pakistan arrest, expel or bring to the negotiating table Taliban leadership," Wells said in response to a question from Congresswoman Ileana Ros-Lehtinen.

Ros-Lehtinen, the Congresswoman from Florida, asked Wells if she has seen any evidence that Pakistan has taken any steps to cut off the flow of arms, of fighters or support for the Taliban.

"Have we in the US allowed for any waivers or made any exceptions to military assistance to Pakistan since the suspension of the aid was announced?" the lawmaker asked.

Responding to another question from Congressman Ted Poe, Wells said she agrees with the assessment that the biggest problem in Afghanistan are the sanctuaries in Pakistan that shelter terrorists.

"The Pakistan government has hidden terrorist leaders in the past, they're a sanctuary for terrorist leaders, and somehow we still give Pakistan money with the promise that they will do better. They sweet talk us and say, 'Oh, give us more American aid, we will go after the terrorists'. We do that every year, we continue to do it, we've done it for I don't know how many years, 17, and yet nothing changes," Poe said.

"They harbour terrorists. They fight terrorists in their country, but they pay for terrorists to go across the border into Afghanistan that kills Americans and our allies and Afghans. I think it is nonsense that we continue to send money to Pakistan," he said.

Congresswoman Ann Wagner said that Pakistan has a clear interest in preventing the cessation of hostilities in Afghanistan, but has made itself central to American operations.

In the past, Pakistan has wagered, correctly, that the US would rather accept Pakistan incomplete support than lose it entirely.

"I believe the president was correct to demand full cooperation from Pakistan last August," she said.

Under the Trump administration, Wells said the US not only had direct talks with the senior leadership of Pakistan, but also has taken the unprecedented step of suspending military assistance and coalition support funds, as a result of US assessment that Pakistan had not been undertaking the decisive and sustained steps that are necessary.

"We agree that Pakistan has a lot to gain by peace in Afghanistan. And so, the challenge is, how do you secure Pakistan's support for a negotiated political process, rather than its tolerance of proxies?" she said.

She said Pakistan can't be a normal state as long as there are extremist groups on its soil.

"We do not deny that Pakistan has fought its own heroic battles against terrorism. It defeated, in large part, the Pakistani Taliban. It's just now reintegrated the federally administered tribal areas into the governing system of Pakistan. But, you know, we treat all terrorist enemies of Pakistan as our terrorist enemies and we expect that Pakistan should do the same," Wells said.

Unveiling his new South Asia strategy in August last year, Trump had accused Pakistan of giving "safe haven to agents of chaos, violence, and terror," and said the time had come "for Pakistan to demonstrate its commitment to civilisation, order, and to peace".