The Republican party is facing a divide, with party leader Paul Ryan refusing to support Donald Trump as the party's presidential nominee, insisting that the businessman must do more to unite the party.
Appearing on CNN's show The Lead, Ryan, the speaker of the House of Representatives, said on Thursday that many Republicans wanted to see "a standard-bearer who bears our standards" and "unifies all the wings of the Republican Party".
"I'm just not ready to do that at this point. I'm not there right now," the Wisconsin Republican said.
Al Jazeera's Kimberly Halkett, reporting from Washington DC, said "Ryan has been asked on national TV whether or not there were concerns about the policy proposals put forward by Donald Trump to not allow Muslims to enter United States, at least temporarily, also to deport illegal immigrants."
"Paul Ryan simply said there is a lot of work that needs to be done," she said.
Donald Trump, since becoming the presumptive Republican nominee has been quietly reaching out to the members of the Republican Party, in an attempt to try and unite the party.
"But he has been receiving a less than warm reception," said Halkett, "Paul Ryan basically said on national TV that he is not ready to support Donald Trump."
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Ryan's comments comes two days after Trump essentially clinched the nomination with a commanding win in Indiana that forced his last two opponents - Ted Cruz and John Kasich - from the race.
Trump, who has become party's presumptive presidential nominee, responded by saying he is not ready to support Ryan's agenda either.
"Perhaps in the future we can work together," the billionaire businessman added.
Unifying the party
Ryan is not the only one to have aired opposition to Trump. Former Presidents George H W Bush and George W Bush and several other senior Republicans have refused to back the real estate mogul.
But Indiana Governor Mike Pence and former Texas Governor Rick Perry threw their weight behind the presidential nominee.
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Republican National Committee Chairman Reince Priebus, however, said that Ryan and Trump will work out their differences after he spoke to both of them.
The highly unusual salvos between the likely White House nominee and the House speaker came at a moment when all involved would normally be turning from the primaries to unifying the party for November's elections.
Ryan, his party's 2012 vice presidential nominee, had been seen as a possible "white knight" candidate who could emerge as an alternative to Trump at a contested convention slated to be held in July. He called a press conference last month to rule himself out.
Trump's Indiana victory pushed him to 1,047 delegates. He needs 1,237 to clinch the nomination.
Source: Al Jazeera and agencies