Allies of President Donald Trump are reportedly worried about Vice President Mike Pence and United Nations ambassador Nikki Haley getting too close, as they fear they could backstab the president ahead of his 2020 reelection bid.

A New York Times report claims that "Republicans close to the White House" are whispering "about the prospect of an alliance between Haley and Vice President Mike Pence, possibly to run as a ticket in 2020." Times reporter Maggie Haberman similarly writes on Twitter that "the prospect of a Pence-Haley political alliance raised ire of people close to Trump."

What has spooked Trump allies, according to the report, was Pence's recent decision to hire longtime Trump critic Jon Lerner as his own national security adviser -- a move that Trump angrily squashed after he learned that Lerner had made anti-Trump ads on behalf of the right-wing Club for Growth during the 2016 Republican primaries.

Haley, meanwhile, has been openly feuding with the White House after she said on Sunday that there would be additional sanctions levied against Russia -- only to be shot down by Trump one day after her announcement.