(AP) - President Donald Trump is claiming that an Obama era uranium deal with Russia is a scandal on par with Watergate.

And he's promising that the Republican donor who funded the compiling of a dossier on him will be revealed.

The uranium deal involves the purchase of American uranium mines by a Russian-backed company in 2010. Trump says that sale - reached while Hillary Clinton was secretary of state - was "so underhanded" and that it's "Watergate modern age."

Some investors in the company had relationships with former President Bill Clinton and donated to the Clinton Foundation.

Trump's comments follow the revelation that Hillary Clinton's 2016 campaign and the Democratic National Committee paid for the creation of a political dossier on Trump.

A Republican donor who opposed Trump reportedly paid for the dossier in the beginning of the campaign, but the research firm behind the dossier has refused to reveal that person's identity.

Trump thinks the name "probably be revealed" eventually.