US President Barack Obama has issued a sharp criticism of Republican presidential nominee Donald Trump, calling him “unfit” to be president.
Obama made the comments on Tuesday during a White House news conference with Singapore's prime minister, Lee Hsien Loong, after Trump criticized an American Muslim family whose son was killed in Iraq.
Obama also challenged Republican leaders to withdraw support for Trump for his criticism of Khizr and Ghazala Khan, who appeared at the Democratic National Convention (DNC) last week.
During the DNC address, Khizr Khan denounced Trump as unpatriotic and selfish over his divisive rhetoric against immigrants and Muslims.
Trump responded, in part, by suggesting that Ghazala Khan, the mother of the fallen soldier, was silent during her husband’s speech at the DNC because she was not “allowed” to speak.
Ghazala Khan said that she did not intend to speak during the convention because she would get emotional.
"The notion that he would attack a Gold Star family that had made such extraordinary sacrifices on behalf or 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," Obama said of Trump.
Families who lose sons or daughters who serve in the US military are called Gold Star families.
Obama, who is a Democrat, noted that Republican leaders, including Senate Republican leader Mitch McConnell, Speaker of the House of Representatives Paul Ryan, and senator John McCain, a one-time Republican presidential nominee, have criticized Trump for his remarks but have stood by their endorsements of him.
"The question I think that they have to ask themselves is, if you are repeatedly having to say in very strong terms that what he has said is unacceptable, why are you still endorsing him?" Obama said.
"What does this say about your party that this is your standard-bearer?" he asked.
Obama has endorsed the Democratic nominee and his former secretary of state, Hillary Clinton.
A Gallup poll released early last month found that Trump and Clinton are among the worst-rated presidential candidates of the last 70 years.