Updated at 2:20 p.m. ET following Trump's press conference
Donald Trump is "totally pledging" his allegiance to the GOP and promising not to mount a potentially damaging third-party bid for president.
The billionaire businessman said Thursday he had signed the Republican National Committee's "Loyalty Pledge," which says he will support the eventual nominee and not run as an independent or on another party line.
"I will be totally pledging my allegiance to the Republican Party and the conservative principles for which it stands," said Trump.