Washington DC - President Donald Trump launched a scathing attack on Republican Senate Majority Leader John Thune for refusing to alter filibuster rules to force through a vote on the SAVE America Act.

"Well, he's got to be a leader," Trump said of Thune to reporters outside the White House on Wednesday. "He's a leader; he's got to get them. It's the most popular I've ever seen put before Congress."

Trump's comments came after a reporter asked about Thune's refusal to hold a vote in the Senate on the president's Safeguard American Voter Eligibility Act (SAVE America Act) because he has yet to whip up enough votes for it to pass.

"It's voter ID, it's voter – you have to be able to be a citizen to vote; you've got to. It's called citizenship," the president rambled.

"And we are also adding in no men playing in women's sports, no transgender mutilation of our children, and no mail-in ballots, fake mail-in ballots; we'll have none of that except in the case of the military."

While the House of Representatives approved a version of the bill in February, the SAVE America Act has been held up in the Senate because filibuster rules require a supermajority of 60 votes for it to pass.

In response, Trump has pressured Thune to bring forward a "talking" filibuster, effectively forcing the Democrats to hold the Senate floor.

"We don't have the votes either to proceed with a talking filibuster or to sustain one if we got one," Thune said on Tuesday. "That's just a function of math."

"We're going to have the fight on the floor," he said. "We're going to vote on this. I can guarantee the debate, I can guarantee the vote; I just can't guarantee an outcome."