"Paul Ryan should spend more time on balancing the budget, jobs and illegal immigration and not waste his time on fighting Republican nominee," Trump wrote.
Ryan told House Republicans on a call that will focus only on maintaining GOP control of both houses of Congress. He hinted that he may think the presidential race is out of reach for Trump, saying that he wants to ensure Democrat Hillary Clinton does not get a blank check with Congress, according to NBC News. He said representatives need to do what is best in their districts.
But the House speaker has not pulled his endorsement of Trump, a Ryan spokeswoman told NBC News.
His decision follows outrage over a leaked 2005 video that shows the GOP presidential nominee crudely joking about groping women without consent. Following the video's release on Friday, numerous Republican lawmakers said they would not back Trump, though Ryan and Senate Majority Leader Mitch McConnell have not explicitly rescinded their support. Ryan previously pulled Trump's invitation to a campaign event in Wisconsin over the weekend.
The fallout from the leaked video fueled speculation that the Republican Party could pull back on resources to help elect Trump, instead focusing on keeping congressional majorities. Association with Trump could be seen as toxic for some Republicans in tight congressional races.
But Trump's frequent and aggressive appeals in Sunday night's debate to the supporters who fueled his unlikely political rise only complicated matters for candidates who want to keep their distance from him.