Donald Trump in talks with Republican leaders after broken pledge
Republican pace-setter Donald Trump has held talks with party leaders as tensions grow over his loyalty and policies in his presidential bid.
His meeting at the Republican National Committee (RNC) in Washington lasted 30 minutes but details were scant.
Earlier in the week, Mr Trump said he would not back the eventual Republican candidate, breaking an RNC pledge he signed in the autumn.
"I have been treated very unfairly. By basically the RNC," Mr Trump told CNN.
Since that interview, he has had a terrible few days, with an aide charged by police over a clash with a reporter and his own remarks about abortion widely condemned.
The next test in the state-by-state contest to find a presidential candidate is on Tuesday in Wisconsin, where Mr Trump trails Texas Senator Ted Cruz in the polls.
Sources present at the RNC meeting on Thursday afternoon told CNN and Bloomberg that it focused on the summer convention ahead, and the pledge and abortion remarks were not discussed.
"The chairman and Mr. Trump had a productive conversation about the state of the race," said RNC spokeswoman, Lindsay Walters.
Mr Trump tweeted after the meeting that it was "very nice".
Mr Trump is trying to avoid a brokered convention in July, which would take place if he does not receive the 1,237 delegates needed to secure the nomination.
In such a scenario, party delegates would choose the nominee at the convention, meaning Trump could lose out on the nomination despite earning the most delegates.
Ohio Governor John Kasich or Mr Cruz could win the nomination this way, with many in the Republican party uncomfortable with Mr Trump's performance on the campaign trail.
The US political world is still reverberating from the backlash prompted by Mr Trump's comments on abortion, when he said women should be punished if the practice became illegal.
He later backtracked after an explosion of criticism and said the doctor should be held responsible instead.
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Tensions have also surfaced in the Democratic race, with Hillary Clinton accusing the Bernie Sanders campaign of "lies".
The former US secretary of state and first lady snapped at a Greenpeace activist who asked her if she would stop taking campaign contributions from the fossil fuel industry.
Raising her voice and pointing her finger in a rare flash of anger, she said: "I am so sick of the Sanders campaign lying about me."
A spokeswoman for the Clinton campaign later said she had accepted no cash from oil and gas companies, only from individuals who work in those industries.
But the Sanders campaign hit back, saying 57 lobbyists from the industry have personally given large sums to her campaign.