Close call as Donald Trump and Hillary Clinton campaign in Ohio
Donald Trump and Hillary Clinton made rival Labour Day campaign pitches in Ohio - with their planes parked on the same tarmac.
Mr Trump and his running mate, Mike Pence, prepared to leave Cleveland as Mrs Clinton and Tim Kaine arrived.
It was a near-encounter that even forced the Trump press team to the side of the road as Mrs Clinton's motorcade whizzed by.
"It's kind of interesting to have all the planes here on the same tarmac," Mr Kaine said as he walked over to greet Mrs Clinton. "Just shows you how important Ohio is. We're going to be here a lot."
Mrs Clinton and Mr Kaine planned to take part in a Labour Day festival with union leaders and workers in Cleveland before travelling to Illinois.
Mr Trump and Mr Pence attended a round-table discussion with union members, during which Mr Trump warned that America's manufacturing jobs are "going to hell".
Mr Trump also appeared with Democratic Mayor Tom Coyne, of Brook Park, Ohio, who said he supported Mr Trump in this spring's Republican primary and would vote for him this autumn.
"The mayor today is just one example of what's happening across this country," Mr Trump campaign manager Kellyanne Conway said. "Voters who traditionally have not voted Republican or haven't even voted in a very long time seem to be coming out to support this messenger and this message."
While Labour Day has traditionally been the kick-off to the autumn campaign, both Mrs Clinton and Mr Trump have been locked in an intense back-and-forth throughout the summer.
Mrs Clinton arrived in Ohio aboard a new blue-and-white Boeing 737 campaign plane emblazoned with her slogan, "Stronger Together". She has mostly travelled by private jet during the primaries and the summer but was being accompanied on the plane by journalists for the first time. "It's so exciting," she told journalists as they boarded her plane.
Mrs Clinton has been pressured by media critics and Republicans alike to hold a news conference for the first time in 2016. She has not held a formal question-and-answer session with reporters since one in Iowa in early December.
As he left Cleveland for his next stop in Youngstown, Mr Trump extended a rare invitation to a handful of journalists on his private jet, and said that "on occasion," he will invite journalists to travel with him.
"It doesn't have to be all the time," he added.
He said that his message to voters will be "all about jobs now". Asked whether he will be pressing some of his controversial policy views on immigration, Mr Trump said: "I think I've got that issue very well covered."
No Republican has won the White House without winning Ohio and Mr Trump is trying to overcome some splintering in the state party, which was supportive of Ohio Governor John Kasich during the presidential primary.
Mrs Clinton has questioned Mr Trump's temperament and preparation to serve as commander in chief while seeking to connect the reality television star to the extreme "alt-right" movement within the Republican Party.
Mr Trump visited a predominantly black church in Detroit on Saturday in a rare appearance with minority voters, aiming to counter Mrs Clinton's argument to moderate and suburban voters that he has allowed a racist fringe to influence his candidacy.
The start of fully fledged campaigning opens a pivotal month, culminating in the first presidential debate on September 26 at Hofstra University in Hempstead, New York. Polls show Mr Trump trailing Mrs Clinton in a series of must-win battleground states, meaning the debates could be his best chance at reorienting the race.
Mr Trump told reporters that he does plan to take part in all three presidential debates, joking that only a "hurricane" or "natural disaster" would prevent him from attending.
Mrs Clinton will have millions of dollars at her disposal this autumn to air television advertising.
The former secretary of state raised a combined 143 million dollars (£107 million) in August for her campaign, the Democratic National Committee and state parties - her best month yet. She began September with more than 68 million dollars (£51 million) in her campaign's bank account to use against Mr Trump, who has not yet released initial fundraising totals for August.
Democrats were fanning out across battleground states, dispatching Mr Kaine and Vice President Joe Biden to Pittsburgh, former president Bill Clinton to Detroit and Cincinnati and one-time Clinton primary rival Bernie Sanders to New Hampshire.
Mr Clinton told a crowd of union workers at the UAW's Labour Day picnic in Detroit that Mr Trump's economic policies have been tried before - cutting taxes on the rich, doubling the national debt and loosening financial industry regulations.
"The last time we did that kind of stuff, it didn't work out too well for us," he said.