US election 2016: Republican candidate Donald Trump has said he is going to target states seen as Democratic strongholds in the last two days before the US election.
He will visit Pennsylvania, Michigan and also Minnesota, which has not gone Republican since 1972.
On Saturday evening, he was briefly rushed off the stage by secret service agents at a rally in Reno, Nevada.
Mr Trump had stopped speaking after seeing something in the auditorium, but returned to the stage minutes later.
A man was held on the ground by local law enforcement officers before being searched and led away.
There were reports that the man had a gun, but the secret service later said that “upon a thorough search of the subject and the surrounding area, no weapon was found”.
When he resumed his speech, Mr Trump said: “Nobody said it was going to be easy for us… I want to thank the Secret Service.”
At the scene: The BBC’s James Cook in Reno, Nevada
Donald Trump was approaching the climax of his speech inside a packed hall in Reno when suddenly there was a commotion near the stage. Secret service agents rushed towards the property tycoon and he was rapidly hustled from the auditorium.
For a short time there was panic among supporters of the Republican candidate with some people running for the exits amid an unconfirmed rumour of a gun in the crowd. The sense of alarm was heightened when soldiers in desert camouflage moved in. Seconds later a bald white man was escorted from the venue.
A few minutes later Mr Trump returned to the stage, apparently unfazed, thanking the secret service and completing his speech before leaving for his next stop on the campaign trail.
Earlier, Mr Trump had started off a four-state swing in Florida, where rival Hillary Clinton also campaigned.
She unveiled an advert to run in nearly a dozen states, set to the Katy Perry song, Roar.
Mrs Clinton later appeared with Perry at a rally in Philadelphia, Pennsylvania, where the Democratic presidential candidate urged the crowd to vote.
“When your kids and grandkids ask you what you did in 2016,” Mrs Clinton said, “I want you to be able to say, I voted for a better, stronger, fairer America.”
Perry, who took to the stage to sing the song Nasty, said she was looking forward to election day. “Tuesday’s going to be fun,” she said, “but Wednesday is going to be better.”
Opinion polls suggest Mrs Clinton is still ahead in key states.
But she has seen her lead slip following last week’s FBI announcement that it was looking into emails that may be connected to her use of a private email server while she was secretary of state.