WASHINGTON/ISLAMABAD (Reuters) - The United States accused Pakistan on Tuesday of playing a “double game” on fighting terrorism and warned Islamabad it would have to do more if it wanted to maintain U.S. aid.

“They can do more to stop terrorism and we want them to do that,” White House spokeswoman Sarah Sanders told reporters.

The White House said it would likely announce actions to pressure Pakistan within days, shortly after U.S. Ambassador Nikki Haley said at the United Nations that Washington would withhold $255 million in assistance to Pakistan.

“There are clear reasons for this. Pakistan has played a double game for years,” Haley told reporters. “They work with us at times, and they also harbor the terrorists that attack our troops in Afghanistan.

“That game is not acceptable to this administration. We expect far more cooperation from Pakistan in the fight against terrorism.”

The comments followed an angry tweet from President Donald Trump on Monday that the United States had been rewarded with “nothing but lies and deceit” for “foolishly” giving Pakistan more than $33 billion in aid in the past 15 years.

“They give safe haven to the terrorists we hunt in Afghanistan, with little help. No more!” he tweeted.

Pakistan civilian and military chiefs on Tuesday rejected “incomprehensible” U.S. comments and summoned American Ambassador David Hale to explain Trump’s tweet.

Pakistani U.N. Ambassador Maleeha Lodhi said in a statement that her country’s fight against terrorism was not based on any consideration of aid but on national interests and principles.

“We have contributed and sacrificed the most in fighting international terrorism and carried out the largest counter terrorism operation anywhere in the world,” Lodhi said. “We can review our cooperation if it is not appreciated.”

Relations with Washington have been strained for years over Islamabad’s alleged support for Haqqani network militants, who are allied with the Afghan Taliban.

The United States also alleges that senior Afghan Taliban commanders live on Pakistani soil, and has signaled it will cut aid and take other steps if Islamabad does not stop helping or turning a blind eye to Haqqani militants crossing the border to carry out attacks in Afghanistan.

In 2016, Taliban leader Mullah Mansour was killed by a U.S. drone strike inside Pakistan and in 2011, al Qaeda leader Osama bin Laden was found and killed by U.S. troops in the garrison town of Abbottabad.

FILE PHOTO: U.S. President Donald Trump talks to reporters before departing the White House for a visit to the Walter Reed Medical Center in Washington, DC, U.S., December 21, 2017. REUTERS/Jim Bourg/File Photo

STATE DEPT: PAKISTAN NEEDS TO EARN AID

At the State Department on Tuesday, spokeswoman Heather Nauert said Pakistan knew what it needed to do, including taking action against the Haqqani network and other militants.

Pakistan needs to “earn, essentially, the money that we have provided in the past in foreign military assistance,” she said.

Islamabad bristles at the suggestion it is not doing enough to fight militants, noting that its casualties at the hands of Islamists since 2001 number in the tens of thousands.

Pakistani Prime Minister Shahid Khaqan Abbasi on Tuesday chaired a National Security Committee meeting of civilian and military chiefs, focusing on Trump’s tweet. The meeting, which lasted nearly three hours, was brought forward by a day and followed an earlier meeting of army generals.

The committee, in a statement issued by the prime minister’s office, did not name Trump but spoke of “deep disappointment” at a slew of critical comments from U.S. officials over the past few months.

“Recent statements and articulation by the American leadership were completely incomprehensible as they contradicted facts manifestly, struck with great insensitivity at the trust between two nations built over generations, and negated the decades of sacrifices made by the Pakistani nation,” it said.