By Elizabeth Pineau and Dominique Vidalon

PARIS (Reuters) -The European Union and France on Monday announced half a billion euros worth of incentives to lure scientists to the continent, seeking to profit from U.S. President Donald Trump's federal funding cuts and clashes with top U.S. universities.

"We call on researchers worldwide to unite and join us ... If you love freedom, come and help us stay free," French President Emmanuel Macron said at Paris' Sorbonne University alongside European Commission President Ursula von der Leyen.

The money would fund research projects and help universities cover the cost of bringing foreign scientists over to help run them, officials said.

Von der Leyen announced the 500 million euros ($566.6 million) incentive package and said she also wanted EU member states to invest 3% of gross domestic product in research and development by 2030.

Macron pledged 100 million from France, though it was not immediately clear if this came on top of the EU pledge.

Trump has targeted U.S. universities since taking office in January by freezing federal funding, launching investigations, revoking international students' visas and making other demands.

Trump, a Republican, has said higher education has been gripped by what he calls antisemitic, anti-American, Marxist and radical left ideologies.

Last week, he said his administration will revoke Harvard University's tax-exempt status, a move that Harvard said would be an unlawful misuse of the U.S. tax code.

'REVERSE BRAIN DRAIN'

Robert N. Proctor, a historian at Stanford University, told Reuters that Trump was leading "a libertarian right-wing assault on the scientific enterprise" that had been years in the making.

"We could well see a reverse brain drain," he said. "It's not just to Europe, but scholars are moving to Canada and Asia as well."

Meredith Whittaker, the president of encrypted messaging app Signal, declined to comment on geopolitical disputes. But she told Reuters it was inevitable top talent would gravitate to welcoming jurisdictions.

"I think researchers, people whose lives, whose inquiry, whose obsessions are motivated by particular questions, particular fields, who exist in a community of intellectual practice, will always be attracted to places where the ground is fertile for that work, where they're not threatened, and where their research isn't hampered or perverted," she said.

The threat to academics' livelihoods at U.S. universities including Yale, Columbia and Johns Hopkins has given Europe's political leaders hope they could reap an intellectual windfall.

But with European universities far less wealthy than their U.S. peers, it remains to be seen if they can bridge the funding gap that is needed to attract top U.S. researchers.

Last month, Macron and Von der Leyen said they would be looking to invite scientists and researchers from the world to Europe.

In April, France also launched the "Choose France for Science" platform, operated by the French National Research Agency, which enables universities, schools, and research organisations to apply for co-funding from the government to host researchers.

($1 = 0.8825 euros)

(Additional reporting by Sudip Kar-Gupta; Editing by Gabriel Stargardter and Andrew Heavens)