US President Donald Trump speaks while signing executive orders at the White House in Washington January 24, 2017. [Photo/Agencies]

An executive action commissioning the probe is still planned but could be several weeks away, two senior administration officials said Friday. Although Trump instructed staff to jump on the project last week, he has not discussed the issue in recent days, according to two other people in close touch with the president. All demanded anonymity to discuss private conservations.

Asked about the status of the effort, White House spokeswoman Lindsay Walters said: "I do not have an update at this time."The indefinite delay comes as some of Trump's advisers counseled him to abandon the idea, arguing it was a distraction from more pressing issues. There is no evidence of widespread voter fraud in last November's election. Trump won the Electoral College vote but lost the popular vote by nearly 2.9 million votes to Democrat Hillary Clinton.

The episode is a striking example of the new president's mercurial streak and his willingness to impulsively seize on ideas with little planning and sometimes later reverse course when encountering obstacles or criticism.

A senior official said the investigation, which Trump never publicly discussed in detail, has become less of a priority because it has been drowned out by other White House efforts, including attempts to manage the chaotic aftermath of Trump's executive order restricting immigration from seven Muslim-majority nations. The investigation likely would not considered until well after the confirmation of Trump's pick for attorney general, Republican Sen. Jeff Sessions of Alabama, the official said.

That would be a marked change from the breakneck pace by which the order was first introduced.

In his earliest days in office, Trump appeared to be fixated on the election results and frustrated by political opponents who questioned the legitimacy of his victory.

At his first meeting with bipartisan lawmakers, he declared believed that 3 million to 5 million people voted illegally in November, a widely debunked assertion that sent the White House scrambling to craft an order that met the president's wishes.

Two days later, Trump announced in a pair of tweets that a "major investigation" will look at those registered to vote in more than one state, "those who are illegal and ... even, those registered to vote who are dead (and many for a long time)." Depending on results, the Republican tweeted on his sixth day in office, "we will strengthen up voting procedures!"Several congressional Republicans decried the claim as a distraction, other executive orders were rescheduled and an administration set to roll out an ambitious first-week agenda found itself suddenly sidetracked.