President Donald Trump is expected to sign an executive order today establishing a commission to review alleged voter fraud and voter suppression in the American election system, multiple senior administration officials tell ABC News.

The officials say Vice President Mike Pence and Kansas Secretary of State Kris Kobach will be announced as Chair and Vice Chair of the ‘Presidential Commission on Election Integrity’ in a press release today. It's not clear whether the White House will allow coverage of the order signing.

The commission, which will include Republicans and Democrats, will be tasked with studying "vulnerabilities" in U.S. voting systems and potential effects on "improper voting, fraudulent voter registrations and fraudulent voting," according to one official with knowledge of the announcement.

In the aftermath of the 2016 election, Trump claimed widespread voter fraud explained why former Secretary of State Hillary Clinton emerged with nearly 3 million more popular votes. To date, neither Trump nor his team has provided evidence to substantiate the claims, but they have promised an investigation.

“You can never really find, you know, there are going to be -- no matter what numbers we come up with there are going to be lots of people that did things that we're not going to find out about,” Trump told ABC News' David Muir in January. "But we will find out because we need a better system where that can't happen."

Administration officials would not provide a draft copy of the order but described its scope to ABC News. The commission's review is expected be broad in scope, and will not just address Trump's allegations about the 2016 election but also "systemic issues that have been raised over many years in terms of the integrity of the elections," one official said.

Membership of the commission is still taking shape even as Trump is poised to sign the order creating it. Indiana Secretary of State Connie Lawson (R), New Hampshire Secretary of State Bill Gardner (D), Maine Secretary of State Matthew Dunlap (D), Christie McCormick, commissioner of the election assistance commission, and former Ohio Secretary of State Ken Blackwell (R), are among the names under consideration, the administration officials said.

The commission will also examine the issue of voter suppression, officials said, which could encourage Democrats to sign on to the effort.

The commission is tasked with submitting a report on its findings sometime in 2018, officials said, and is expected to meet for the first time this summer.

The announcement is the latest indication that the president intends to pursue action, as promised, on his controversial and so-far unsubstantiated assertion that "millions" of people illegally cast ballots in the 2016 presidential election.

The president first raised the issue in a tweet in late November of 2016 claiming it resulted in his loss in the popular vote by nearly 3 million votes.