Donald Trump won't pardon former sheriff Joe Arpaio during his visit to Arizona, the White House has confirmed, as supporters and protesters gathered at the site of the president's latest campaign rally.
Outside the Phoenix convention centre, shouting matches and minor scuffles erupted between the two sides. Phoenix Mayor Greg Stanton had asked Mr Trump to delay his political event to allow for more time of national healing.
It's the first Trump campaign rally since a violent Charlottesville, Virginia, protest organised by white supremacists led to three deaths.
Eager to capitalise on his hard-line stance on immigration, Mr Trump had teased the politically inflammatory possibility of pardoning Arpaio. The former Maricopa County sheriff is awaiting sentencing after his conviction in federal court for disobeying court orders to stop his immigration patrols.
White House press secretary Sarah Huckabee Sanders said Mr Trump won't discuss or take action on a pardon "at any point today".
The president began his Arizona visit with a brief trip to the southern edge of the country.
While touring a Marine Corps base in Yuma that is a hub of operations for the US Border Patrol, Mr Trump inspected a drone and other border equipment on display in a hangar.
Afterward, he spent about 20 minutes greeting service members in the gruelling, 106-degree heat, signing caps with his "Make America Great Again" campaign slogan and posing for selfies on the tarmac just steps from Air Force One.
While Mr Trump did not talk publicly about getting tough on immigration during his Yuma visit, the topic was sure to come up at Tuesday's rally - his eighth such event since taking office in January.
The events are organised by his 2020 re-election campaign, which carefully screens attendees.
In the comfort of his most fervent fans, Mr Trump often resurrects his free-wheeling 2016 campaign style, pinging insults at perceived enemies such as the media and meandering from topic to topic without a clear theme.
Vice President Mike Pence, who will introduce Mr Trump at the rally, said the president will be "completely focused" on his agenda for the country.
"He's also going to call on the Congress to get ready to come back when they arrive on September 5th and go straight to work to make America safe again, make America prosperous again, and in his words, to make America great again," Mr Pence said in a Tuesday interview with Fox News.
The vice president travelled to Phoenix separately and bounded up the stairs of Air Force One to greet Trump on the tarmac.
Outside the convention centre, police officers formed a line in the middle of a street to separate the protesters and Trump supporters.
Tuesday's events put Mr Trump in more comfortable political territory than in recent days.
Upending a campaign vow to end the country's longest war, Mr Trump on Monday announced in a national address a plan to maintain to a US military presence in Afghanistan.
Senior US officials said Mr Trump's strategy may involve sending up to 3900 more troops, with some deployments beginning almost immediately.