Aides in two congressional offices said the State Department called on Wednesday to inform them that it would announce on Wednesday or Thursday that aid was being cut off, although it was not clear how much, what type or for how long.
White House spokeswoman Sarah Sanders declined to say whether an announcement was imminent. The State Department did not immediately respond to a request for comment.
The calls to Capitol Hill came a day after Washington accused Pakistan of playing a "double game" on fighting terrorism and warned Islamabad it would have to do more if it wanted to maintain US aid.
US Ambassador to the United Nations Nikki Haley said on Tuesday that Washington would withhold $255 million in assistance to Pakistan. Her statement followed an angry tweet from Trump on Monday that the United States had been rewarded with "nothing but lies and deceit" for giving Pakistan billions in aid.
Pakistan civilian and military chiefs rejected what they termed "incomprehensible" US comments and summoned US Ambassador David Hale to explain Trump's tweet.
Relations between Islamabad and 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.
Many members of the US Congress, particularly Republicans, who control both houses of the legislature, have been critical of the Pakistani government and called for cuts in military and other aid.