Washington, Jan 25 (IANS): US President Donald Trump on Wednesday called for "a major investigation" into "voter fraud" in the 2016 election, after his claims earlier this week, without citing any evidence, that millions of illegal votes were cast during the November polls.

"I will be asking for a major investigation into VOTER FRAUD, including those registered to vote in two states, those who are illegal and ... even, those registered to vote who are dead (and many for a long time). Depending on results, we will strengthen up voting procedures!" Trump wrote in two consecutive tweets.

Trump's comments on voter fraud came on Monday during a meeting with Congressional leaders.

On Tuesday, Trump's press secretary Sean Spicer vigorously defended Trump's statement about illegal voters, though neither Trump nor his surrogates could provide evidence that any substantial illegal voting had occurred or influence the popular vote.

Ohio's secretary of state responded to Trump's tweet on Wednesday, saying his office already investigated claims of voter fraud.

"We conducted a review 4 years ago in Ohio & already have a statewide review of 2016 election underway. Easy to vote, hard to cheat #Ohio," Jon Husted, a Republican, tweeted.

Former Democratic National Committee chair Representative Debbie-Wasserman Schultz issued a harsh condemnation of Trump's call for an investigation, telling CNN's "New Day" that the tweet's message was "deeply disturbing."

"He seems to be questioning the legitimacy of his own election, all while, for the last couple of months, touting how legitimate and huge his election was and historic it is. It can't be both," she said.

"What is the most deeply disturbing about his penchant for lying is -- if he is willing to lie about the trivial, like crowd size, or the significant, like voter fraud, then what happens if -- God forbid -- we go to war and we have our troops lives on the line and there are casualities? Is he going to send Sean Spicer out to lie about the casualties that have taken place? Are our allies going to be able to trust us?" she said.

And former senior adviser to former President Barack Obama, David Axelrod, told CNN, "It becomes an impetus for those who want to further erode voter protection for people who legitimately want to vote and are facing a series of barriers."

When pushed by the media about whether Trump will call for an investigation into the matter, Spicer said, "maybe we will," adding later that Trump believes in voter fraud based on "studies and information he has."

"The President does believe that, I think he's stated that before, and stated his concern of voter fraud and people voting illegally during the campaign and continues to maintain that belief based on studies and evidence people have brought to him," Spicer said at a press briefing.