Donald Trump has ignited tensions within the Republican Party by refusing to endorse House Speaker Paul Ryan or Senator John McCain - a remarkable display of party division just three months before Election Day.
The Republican presidential nominee told The Washington Post he is "just not quite there yet" when asked about an endorsement of Mr Ryan, who faces a primary election next week.
In doing so, he echoed the House Speaker's comments of almost three months earlier, when the Wisconsin congressman was initially reluctant to embrace Mr Trump as his party's standard bearer.
Mr Trump's statement comes amid intense fallout over his criticism of the family of the late Captain Humayun Khan, a US Army soldier who died in Iraq in 2004.
Just two weeks after a Republican National Convention that tried to focus on party unity, the Trump-driven rifts inside the GOP appear to be intensifying.
On Tuesday, retiring New York Representative Richard Hanna became the first Republican member of Congress to say he will vote for Democrat Hillary Clinton in November instead of Mr Trump.
"He is unfit to serve our party and cannot lead this country," Mr Hanna wrote in a column published in The Post-Standard newspaper of Syracuse, New York. "He is unrepentant in all things."
Hewlett-Packard executive Meg Whitman - a prominent Republican fundraiser - also threw her support behind Mrs Clinton, saying: "Donald Trump's demagoguery has undermined the fabric of our national character."
And the woman who helped shape New Jersey Govenor Chris Christie's national image declared that she is voting for Mrs Clinton.
"As someone who has worked to further the Republican Party's principles for the last 15 years, I believe that we are at a moment where silence isn't an option," former Christie senior aide Maria Comella told CNN.
They join dozens of high-profile GOP leaders who have previously said they would not vote for Trump, including the party's 2012 nominee, Mitt Romney, and former Florida Gov. Jeb Bush.
Veterans and families of fallen soldiers continue to call on Trump to apologise for his treatment of the Khan family, who spoke out against Mr Trump at last week's Democratic National Convention.
Mr Trump said the grieving father had "no right" to criticise him, only later acknowledging their son is a hero.
"If @realDonaldTrump wants to be the Commander in Chief, he needs to act like one. And that can't start until he apologizes to the Khans," Dakota Meyer, one of a handful of living Medal of Honor recipients and former Alaska Govenor Sarah Palin's son-in-law, wrote on Twitter.
Mr Trump invited more tension on Tuesday when he told The Washington Post he is not ready to endorse Ryan in next week's Republican primary contest against Paul Nehlen, praising the underdog for running "a very good campaign".
Tensions were already running high between the two high-profile Republicans, who will have to work together closely should Mr Trump win the presidency.
Mr Ryan's campaign spokesman Zack Roday said: "Neither Speaker Ryan nor anyone on his team has ever asked for Donald Trump's endorsement. And we are confident in a victory next week regardless."