President Obama held a joint news conference on Tuesday with Singapore Prime Minister Lee Hsien Loong.
Asked to comment on GOP nominee Donald Trump's tiff with the Khan family and suggestion that the United States ought to recognize Russia's annexation of Crimea, Obama said he feels Trump "is unfit to serve as president."
"I said so last week and he keeps on proving it," he continued. "The notion that he would attack a Gold Star family that had made such extraordinary sacrifices on behalf of our country, the fact that he doesn't appear to have basic knowledge around critical issues in Europe, in the Middle East, in Asia, means that he's woefully unprepared to do this job."
"Why are you still endorsing him?" Obama asked of prominent Republicans like Speaker Paul Ryan, Senate Majority Leader Mitch McConnell, and Senator John McCain, who he said have made "repeated denunciations of [Trump's] statements."
"This isn't a situation where you have an episodic gaffe," he continued. "This is daily, and weekly, where they are distancing themselves from statements he's making. There has to be a point at which you say, 'This is not somebody I can support for president of the United States, even if he purports to be a member of my party.'"