By David Morgan and Richard Cowan
US House Speaker Paul Ryan says Donald Trump's allegations of bias against a Hispanic judge are the "textbook definition of a racist comment" but has reiterated his support for Trump's White House bid.
Ryan, speaking at an event to unveil US House Republicans' policy proposals on Tuesday (local time), said the comments by the Republican Party's presumptive presidential nominee were unacceptable and indefensible.
"I regret those comments that he made. Claiming a person can't do their job because of their race is sort of like the textbook definition of a racist comment. I think that should be absolutely disavowed," Ryan told reporters.
Nonetheless, Ryan said that a Trump presidency would be preferable to a White House occupied by Democrat Hillary Clinton, the likely Democratic nominee.
Ryan, the country's highest-ranking elected Republican, just last week endorsed Trump's presidential bid after withholding support for weeks in part because of Trump's past controversial statements about Mexicans and Muslims.
Since then, Trump has become embroiled in a new controversy -- over his comments last week about Mexican-American US District Judge Gonzalo Curiel.
The real estate developer is refusing to back down on his comments suggesting that Curiel, who is overseeing fraud lawsuits against Trump University, is biased against him because of his heritage and Trump's campaign statements on preventing illegal immigration from Mexico.
In response to questions, Trump said it was possible a Muslim judge might be similarly biased against him based on his campaign call for a temporary ban on Muslims entering the country.
The controversy overshadowed Ryan's attempt to showcase a new welfare reform plan Republicans hope to run on through the November 8 election and turn into legislation next year if they maintain control of the Senate and House of Representatives.
Other Republican lawmakers also piled on pressure on Trump to stop making incendiary remarks and to focus more on issues that can attract a broader electorate in the general election.
Ryan's counterpart in the Senate, Mitch McConnell, said on Tuesday that Trump should avoid such comments.
On Sunday, McConnell, attacked Trump's remarks about Curiel but stopped short of calling them racist.
Senate Foreign Relations Committee Chairman Bob Corker, who has been supportive of Trump and is as a possible vice presidential candidate, pleaded for Trump to switch gears and focus on defeating Clinton in the five months until the election.
Clinton has secured enough delegates to win the Democratic presidential nomination, according to US media outlets.
But her campaign urged supporters to get to the polls on Tuesday in a swath of late primaries to avoid a loss to Bernie Sanders in California as she seeks to unite Democrats ahead of the November match-up with Trump.