US election: Questions over Trump deportation plan
Republican presidential nominee Donald Trump has signalled he may drop his proposal to deport 11 million people who are living illegally in the US.
His campaign manager Kellyanne Conway said the mass deportation plan, which was a central plank of his campaign, was yet "to be determined".
Her comments at the weekend came after Mr Trump met with a new panel of Hispanic advisers.
He told Fox News on Monday he was not "flip-flopping" but wanted a fair plan.
"We want to come up with a fair but firm process. Fair but firm," he said, without giving specifics.
The businessman was scheduled to deliver a speech on immigration in Colorado on Thursday but his campaign team told US media on Monday afternoon that it has been postponed.
Mr Trump has taken a hardline stance on immigration since the beginning of his campaign, vowing to create a "deportation force" as well as make Mexico pay for the construction of a wall along the US-Mexico border.
While struggling to keep up with Democratic rival Hillary Clinton in the polls, Mr Trump has addressed black and Hispanic voters in recent days with the aim of broadening his support beyond white working-class voters.
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"What he supports is to make sure we enforce the law, that we are respectful of those Americans who are looking for jobs, and that we are fair and humane to those who live among us," Ms Conway told CNN on Sunday.
When asked to clarify if Mr Trump would maintain his position on creating a deportation force, Ms Conway responded: "To be determined."
A U-turn? Anthony Zurcher, BBC News, Washington
Donald Trump has repeatedly said the 11.4 million undocumented immigrants in the US "have to go". Now he may be wavering on that demand. The political risks of such a move - detractors will call it a flip-flop - are enormous.
It will be difficult for Mr Trump to convince Hispanic voters and moderates that his change of heart is authentic. Meanwhile, Mr Trump's core base of support could feel betrayed.
The Republican nominee has survived sometimes contradictory positions - on issues such as gay rights, abortion and the minimum wage - that allow supporters to pick and choose what they think he believes.
His position on illegal immigration, however, is different. It's a central part of his argument that the US working class has been grievously wounded by economic policies implemented by a globalist elite more concerned with profit margins than American jobs.
A reversal here would be akin to his saying that maybe Nafta isn't so bad after all. It would tear at the heart of his message.
Given that Mr Trump's standing with Hispanics - particularly in key battleground states - has been an anchor on his presidential hopes, however, it may be a gamble he's decided to take.
But Mr Trump's running mate, Mike Pence, insisted on Monday that the plan remains unchanged.
"I don't think the message is changing at all. I think people are just getting to know Donald Trump better," Mr Pence said.
Mrs Clinton's campaign later released a statement saying there would be little revision to his immigration plan despite Ms Conway's suggestions.
"Donald Trump's immigration plan remains the same as it's always been - tear apart families and deport 16 million people from the United States," said campaign chair John Podesta.
If the deportation plan is dropped or refashioned, it would not be the first shift in Mr Trump's immigration policy.
His controversial plan to issue a "total and complete shutdown" of Muslims entering the country changed to a ban on countries with a history of terrorism against the US. That switch followed questions raised by constitutional experts.
Last week, the Trump campaign faced a dramatic overhaul with the exit of campaign chairman Paul Manafort as well as the hiring of Breitbart News boss Stephen Bannon as CEO and Ms Conway as campaign manager.