Republican presidential nominee Donald Trump speaks during a campaign rally in Everett, Washington, US on August 30, 2016. Picture taken August 30, 2016. [Photo/Agencies]

WASHINGTON - US Republican presidential nominee Donald Trump will meet Mexican President Enrique Pena Nieto on Wednesday in a hastily arranged visit to Mexico hours before delivering a highly anticipated speech on how he will tackle illegal immigration.

True to Trump's flair for the dramatic, the visit will guarantee widespread news coverage for the former reality TV star. It also carries some risks for him, however, since most foreign visits at the presidential level are long-planned and carefully scripted.

Trump's campaign manager, Kellyanne Conway, speaking on NBC's "Today" show on Wednesday, portrayed the Republican candidate's visit as a "decisive presidential move." Asked if he would speak to his host in the same blunt terms he has used at home, Conway said Trump would be "very presidential."

"I think they'll have a productive conversation today ... about illegal immigration but also trade policy and drugs," she told NBC.

Trump announced the trip on Twitter on Tuesday night and it was confirmed in another tweet by the Mexican government. "I have accepted the invitation of President Enrique Pena Nieto, of Mexico, and look very much forward to meeting him tomorrow," Trump said.

The private meeting, which Trump and his advisers began considering last week after Pena Nieto's invitation, will be Trump's first official interaction with a foreign leader since he began his presidential campaign more than a year ago.

Such trips can be tricky to navigate. Mitt Romney, the 2012 Republican nominee, suffered a number of gaffes during a trip to London, Israel and Poland four years ago.

Pena Nieto has dismissed Trump's demand that Mexico pay for a border wall that the New York businessman has pledged to build if elected on Nov. 8. "There is no way that Mexico could pay for a wall like that," he told CNN on July 10.

Pena Nieto, who has publicly voiced skepticism about Trump, has been enmeshed in a controversy over whether he plagiarized some of his 1991 undergraduate law thesis.

The talks will take place hours before Trump is to give a major speech on Wednesday night as he seeks to straddle a fine line between being tough on illegal immigration but giving moderate voters a reason to give his candidacy a fresh look.

While he has closed the gap in some areas, Trump still trails Democratic rival Hillary Clinton in most opinion polls nationally and in most battleground states with 10 weeks to go until the Nov. 8 election.

Clinton has also been invited to a meeting with Pena Nieto but it is not yet clear if she has accepted, although her spokeswoman took a dim view of Trump's trip.

"What ultimately matters is what Donald Trump says to voters in Arizona, not Mexico, and whether he remains committed to the splitting up of families and deportation of millions," spokeswoman Jennifer Palmieri said in a statement.

NO AMNESTY

Trump was to deliver his remarks at 6 p.m. MST (0100 GMT on Thursday) in Phoenix, Arizona, a state that has been at the heart of the debate over the porous US border with Mexico.

Aides said he would reaffirm his determination to the border wall to curtail new illegal crossings and to quickly deport illegal immigrants who have committed crimes in the United States.

But the central question facing Trump was how he would treat the majority of the 11 million illegal immigrants who have set down roots in their communities and obeyed US laws, an issue that has bedeviled the immigration debate for years.

Conway told MSNBC on Tuesday that Trump was active in drafting his speech and was dead set against any proposal that might be seen as providing amnesty to illegal immigrants.

"The point that Mr. Trump has made again and again is that you don't get amnesty and you don't get legalization since you broke the law to be here in the first place," she said. "But then he also respects it's a complex issue."

Conway told NBC on Wednesday that voters would know exactly where Trump stands on immigration following the speech, including his position on what to do about the 11 million immigrants in the country illegally.

Trump has shown signs of indecision on whether to go ahead with his previous proposal for a "deportation force" to deport the 11 million people, saying there are some "great people" among the immigrant population and that he would like to work with them.

He was pressed in an interview with Fox News host Sean Hannity last week on whether he was open to any steps that might accommodate law-abiding people who had built strong family ties in the United States.

"There certainly can be a softening because we're not looking to hurt people," Trump said in his response. "We want people - we have some great people in this country."

FINE LINE

Suggestions of a softening by Trump and his campaign advisers prompted conservative allies like former Alaska Governor Sarah Palin to caution him against rolling back on a central pledge that helped him defeat 16 rivals for the Republican presidential nomination.

A move by Trump to moderate his stance on immigration could help him attract more support among swing voters in his uphill drive to win in November, but some of his conservative backers could be disenchanted.

"It's vitally important that he not disappoint his supporters because they are the people who are with you through thick and thin and when you start to thin your base in hopes of adding other people to your base, it just never works," said Republican strategist Barry Bennett, a Trump supporter.

Trump has already laid out parts of his immigration policy and they resemble some past Republican attempts at immigration reform, like using an E-verify system to ensure that employers hire properly documented workers, and swift deportation of immigrants who have committed crimes.

He has also vowed to stop some major cities' practice of providing sanctuary for illegal immigrants and to stop immigrants from overstaying their visas.