A top US election official has called on President Donald Trump to share any evidence he has to back his claim that voter fraud caused him and former senator Kelly Ayotte to lose in New Hampshire in 2016.
Trump made his latest claim of voter fraud in November's election during a lunch meeting with US senators, saying Ayotte's re-election bid was spoiled by "thousands" of people from neighbouring Massachusetts voting in New Hampshire, according to media reports.
There is no evidence of people being improperly bused into New Hampshire to vote.
"The scheme the president of the United States alleges would constitute thousands of felony criminal offences under New Hampshire law," Federal Election Commissioner Ellen Weintraub said in a statement.
Democratic presidential nominee Hillary Clinton narrowly won New Hampshire's four electoral votes by nearly 3000 votes, while Ayotte, a Republican like Trump, lost by only 743 votes.
Weintraub, who was appointed by former Republican president George W Bush, asked Trump to "immediately share his evidence with the public and with the appropriate law-enforcement authorities so that his allegations may be investigated promptly and thoroughly".
Following reports of Trump's comments, Democratic senator Jeanne Shaheen said in a statement: "There is absolutely no evidence whatsoever of major voter fraud in New Hampshire's elections.
"President Trump continues to spread a dangerous lie and it's long past time for Republican leadership in New Hampshire to stand up and defend our state's electoral system."
Trump said on Sunday he would put Vice-President Mike Pence in charge of a special commission to investigate voter fraud despite numerous studies showing such fraud is rare in the US.
Ayotte was present for the meeting at the White House with a bipartisan group of 10 senators because she is working with Judge Neil Gorsuch, Trump's Supreme Court nominee, to shepherd him around Capitol Hill for meetings.
During the conversation, Trump had a lighthearted exchange with Ayotte, who withdrew her support from Trump during last year's campaign after audio emerged of him boasting about groping women.
Trump said he wished Ayotte had endorsed him like she had endorsed Gorsuch and also made the comments about voting in New Hampshire.
It's the second time Trump has used a bipartisan meeting with lawmakers to make erroneous claims about voter fraud.
During a congressional leadership meeting at the White House in January, he claimed he would have won the popular vote if not for three million to five million immigrants in the country illegally voting for Clinton.
