US President Donald Trump has spoken out about revelations tying Hillary Clinton's presidential campaign to a dossier of allegations about his ties to Russia.

Hillary Clinton's presidential campaign and the Democratic National Committee helped pay for political research into Donald Trump that ultimately produced a dossier of allegations about his ties to Russia, sources say.

Hillary Clinton's presidential campaign and the Democratic National Committee helped fund political research into President Donald Trump that ultimately produced a dossier of allegations about his ties to Russia, a source has said.