President-elect Donald Trump asserted Sunday that he would have won the US popular vote were it not for "millions of illegal" ballots, while dramatically sharpening his criticism of a recount in Wisconsin, calling it "a waste of time."

With the recount threatening to revive debate about the legitimacy of Trump's victory -- his rival Hillary Clinton won far more popular votes, while he carried the all-important Electoral College count -- Trump and his aides pushed back hard on Sunday.

Trump let fly a series of early-morning tweets in which he quoted Clinton about the need to respect the electoral process, while continuing to wage an extraordinarily public battle over the makeup of his future cabinet.

By late afternoon, Trump furthered that "In addition to winning the Electoral College in a landslide, I won the popular vote if you deduct the millions of people who voted illegally."

Trump had warned before the election that the result might be "rigged," but he had offered no such complaint after his unexpected victory November 8 -- until now.

Neither he nor any of his aides has offered any evidence of the "millions" alleged to have voted illegally, nor did Trump explain why he would oppose a recount if illegal voting was such a serious problem.

No election observers have pointed to any such widespread fraud.

It was the latest bizarre twist in an increasingly rough and jolting presidential transition, with much of it fought on social media and on the nation's television screens.

Trump's top aide Kellyanne Conway, in the middle of the turbulence, appeared on Sunday to at least hint that if the Clinton team pushes too hard on the Wisconsin recount, the president-elect might rethink his vow not to seek Clinton's prosecution for using a private email server when she was secretary of state.

While the recount was requested by Green Party candidate Jill Stein, who received a minute fraction of the total vote in Wisconsin, Clinton's campaign has said it would join the process despite having seen no irregularities in the White House contest so far.

Conway said on ABC that while Trump was being "magnanimous" toward Clinton, "I guess her attitude towards that is to have her counsel go and join this ridiculous recount."

And Reince Priebus, Trump's chief of staff, said that while the president-elect is not "seeking methods and ways to persecute and prosecute Hillary Clinton," Trump would probably be "open to listening" should any new findings against her emerge from future investigations.


Legal right

Bernie Sanders, Clinton's Democratic rival in the primary race and now a member of the Senate leadership, defended the recount.

"The Green Party has the legal right to do it," he said on CNN. "We have recounts probably almost every election. No one expects (there) to be profound change."

Marc Erik Elias, an election lawyer for the Democratic candidate, said in a post on Medium.com on Saturday that the campaign would also participate in recounts in Michigan and Pennsylvania if they are arranged.

Most election experts see almost no chance the election outcome could be reversed -- Clinton trails in each state by several thousand votes.

Trump won Michigan, Pennsylvania and Wisconsin by a total of just over 100,000 votes, even while compiling many more than the 270 votes needed for victory in the Electoral College.


Blowback against Romney

But the dispute continued to roil what has already been a rough transition period, as serious signs of internal discord over cabinet picks again emerged on Sunday.

The discord centers around the position of secretary of state, with some in the Trump camp supporting Mitt Romney, the 2012 Republican presidential nominee, as a more mainstream choice while others favor the more divisive former New York mayor Rudy Giuliani.

In what political analysts considered a highly unusual public airing of those tensions from within the Trump team, Conway last week tweeted that she had received "a deluge" of concern from people warning against Romney.

Asked about that on Sunday, she told NBC that she was not "campaigning" against Romney but was "just astonished at the breathtaking volume and intensity of blowback" to a possible Romney nomination.

Trump supporters were infuriated in March when the former Massachusetts governor delivered a passionately worded attack on Trump on the part of the Republican Party's establishment, calling him a "fraud," given to "absurd third-grade theatrics."

However, the two seemed to have put their differences behind them when they met on November 19 to discuss a possible cabinet position.