Donald Trump reveals his plans on how US would manage entry into country
Donald Trump will call for a new ideological test for admission to the United States, vetting applicants on their stance on issues such as religious freedom, gender equality and gay rights.
The policy would represent a significant shift in how the US manages entry into the country.
In a speech in swing state Ohio, Mr Trump will also call for "foreign policy realism" and an end to nation-building if elected president.
He will argue that the United States needs to work with anyone who shares the mission of destroying Islamic State (IS) and other extremist organisations, regardless of other disagreements.
"Mr Trump's speech will explain that while we can't choose our friends, we must always recognise our enemies," Trump senior policy adviser Stephen Miller said.
The Republican nominee's foreign policy address comes during a rocky stretch for his campaign.
He has struggled to stay on message and has consistently overshadowed his policy rollouts, including an economic speech last week, with provocative statements, including falsely declaring that President Barack Obama was the "founder" of IS.
Democrat Hillary Clinton has spent the summer hammering Mr Trump as unfit to serve as commander in chief.
She has been bolstered by a steady stream of Republican national security experts who argue the billionaire businessman lacks the temperament and knowledge of world affairs to be president.
- Read more: Donald Trump says he'd be beating Hillary Clinton 'by 20%' if it wasn't for 'disgusting and corrupt media'
Mrs Clinton is focusing on domestic themes as she campaigns in Pennsylvania with vice president Joe Biden.
Mr Trump is expected to spend significant time in his speech going after Mr Obama and Mrs Clinton, the former secretary of state, blaming them for policies he argues allowed IS to spread.
Mr Trump is expected to say that any country that wants to work with the US to defeat "radical Islamic terrorism" will be a US ally - though aides did not specify which countries that position refers to.
He will also call for declaring in explicit terms that, like during the Cold War, the US is in an ideological conflict with radical Islam.
Mr Obama, Mrs Clinton and top US officials have warned against using that kind of language to describe the conflict, arguing that it plays into militants' hands.
"Mr Trump will outline his vision for defeating radical Islamic terrorism, and explain how the policies of Obama-Clinton are responsible for the rise of Isis (IS) and the spread of barbarism that has taken the lives of so many," Mr Miller said.
Under Mr Trump's new immigration policy, the government would use questionnaires, social media, interviews with friends and family or other means to determine if applicants support American values such as tolerance and pluralism. The US would stop issuing visas in any case where it cannot perform adequate screenings.
It is unclear how US officials would assess the veracity of responses to the questionnaires or how much manpower it would require to complete such arduous vetting. The campaign has yet to say whether additional screenings would apply to the millions of tourists who spend billions of dollars visiting the United States each year.
It will be the latest version of a policy that began with Mr Trump's unprecedented call to temporarily bar foreign Muslims from entering the country - a religious test that was criticised across party lines as un-American.
Following a massacre at a gay nightclub in Orlando, Florida, in June, Mr Trump introduced a new standard, vowing to "suspend immigration from areas of the world where there is a proven history of terrorism against the United States, Europe or our allies, until we fully understand how to end these threats".
That proposal raised numerous questions that the campaign never clarified, including whether it would apply to citizens of countries such as France, Israel or Ireland, which have suffered recent and past attacks. Mr Trump had promised to release his list of "terror countries" soon. But now, aides say, the campaign needs access to unreleased Department of Homeland Security data to assess exactly where the most serious threats lie.
While Mr Trump has been criticised for failing to lay out detailed policies, aides say Monday's speech will again focus on his broader vision. Additional speeches with more details are expected in coming weeks, they said.
Seeking to beat back criticism of his struggling campaign, Mr Trump and his top advisers have blamed the media for failing to focus on his proposals.
"If the disgusting and corrupt media covered me honestly and didn't put false meaning into the words I say, I would be beating Hillary by 20 percent," he tweeted.