WASHINGTON (REUTERS) - US Defence Secretary James Mattis said on Tuesday (Oct 3) the United States would try "one more time" to work with Pakistan in Afghanistan before President Donald Trump would turn to options to address Islamabad's alleged support for militant groups.

Relations between the two countries have been frayed over the past decade. While officials have long questioned the role Pakistan has played in Afghanistan, the comments by Mattis are likely to cause concern in Islamabad and within the Pakistan military.

"We need to try one more time to make this strategy work with them, by, with and through the Pakistanis, and if our best efforts fail, the President is prepared to take whatever steps are necessary," Mattis said at a House Armed Services Committee hearing.

Mattis added that he would be travelling to Islamabad soon, but did not give more details. "I will fly in and we will continue to try to work with them," Mattis said.

Reuters first reported that possible Trump administration responses being discussed include expanding US drone strikes and perhaps eventually downgrading Pakistan's status as a major non-Nato ally.

When asked by a lawmaker whether revoking of Pakistan's major non-Nato ally was amongst the options being considered to deal with Islamabad, Mattis said: "I am sure it will be."

In a separate Senate hearing on Tuesday, the top US military officer said he believed Pakistan's main spy agency, the Inter-Services Intelligence (ISI) directorate, had ties to militant groups.

"It is clear to me that the ISI has connections with terrorist groups," Marine Corps General Joseph Dunford, chairman of the Joint Chiefs of Staff, told the Senate Armed Services Committee.

The Pakistan embassy in Washington did not immediately respond to a request for comment.

The United States in 2012 designated the Pakistan-based Haqqani network as a terrorist organisation. The year before, US Navy Admiral Mike Mullen, then the top US military officer, caused a stir when he told Congress that the Haqqani network was a "veritable arm" of the ISI directorate.

Pakistan argues that it has done a great deal to help the United States in tracking down terrorists and points out that it has suffered hundreds of deaths in Islamist militant attacks in response to its crackdowns.