Paul Ryan is the latest in a string of party grandees who have declined to back Donald Trump.
Donald Trump, the presumptive Republican presidential nominee, said today he was surprised by the US House speaker's refusal to back his bid for the White House and that the two will meet next week.
In a stunning declaration, Paul Ryan said Thursday he was not yet ready to support the billionaire, signaling a deep rift within the Republican party.
The shock announcement by America's top elected Republican was expected to reverberate throughout the GOP's establishment and its rank and file, amid swirling concerns over whether conservatives will rally around Trump in his expected election matchup against Democrat Hillary Clinton.
"I was really surprised by it. And it's fine. He can do whatever he wants to do. But I was surprised by it," Trump said.
"He talks about unity, but what is this about unity?"
The billionaire real estate mogul added that he and Ryan would be meeting next week.
"I believe it's Wednesday," Trump said of the get-together.
When asked what the two would be discussing he added: "I have absolutely no idea."
Ryan was the Republican vice presidential nominee in 2012 and is currently second in line to the presidency. He will be co-chairman of the Republican presidential nominating convention in July.
Ryan is the latest in a string of party grandees who have declined to back Trump.
Presidents George H.W. Bush and his son George W. Bush have signaled they will not endorse him, while Mitt Romney, the 2012 nominee, is reportedly declining to attend the Republican convention.
Trump won Tuesday's hotly contested Indiana primary, pushing Ted Cruz and John Kasich out of the race and leaving him as the presumptive nominee.