"Mr. President, if it weren't for your presidency, this mill would not be here today," said Anthony Pratt, executive chairman of Pratt Industries, at his company's new paper mill in a small Ohio city best known for being the birthplace of astronaut Neil Armstrong.

The 20-minute program featured Mr. Trump alongside Mr. Pratt and Australian Prime Minister Scott Morrison, all standing before U.S. and Australian flags and giant rolls of paper used to make the corrugated boxes for which Pratt Industries is known.

Mr. Trump's latest trip to Ohio was meant to highlight an Australian-owned business with that nation's prime minister in tow and to tout the investment by Mr. Pratt, a Trump supporter and the richest man in Australia, in an electorally important region.

"I'll tell you about Anthony, he's the most successful man in Australia," Mr. Trump said. "He's my friend and I appreciate it."

He called Mr. Morrison a great friend and ally, and cited the surprise victory earlier this year that secured the conservative prime minister a full term.

"It was supposed to be close but they blew him away," Mr. Trump said.

Pratt Industries has made a major investment in Wapakoneta as part of a pledge Mr. Pratt made in 2017 to invest $2 billion in the Midwest if Mr. Trump were elected.

The President's visit marked the grand opening of Pratt's paper mill. The Georgia-based company, which exclusively manufactures recycled paper, broke ground here in 2018. The second phase of its project, a corrugated box factory, is expected to open in March 2020. Both facilities will employ more than 300 workers and produce more than 300 million boxes per year.

"We're really proud of our asset here, and we want to show it off to the world," said Jay Hennessey, a 56-year-old employee who has helped launch and educate workers at several Pratt plants in the U.S. "Then we're going to do it again and again and again."

"We proudly declare Pratt Industries and the great, great state of Ohio open for business...Pratt has pledged, as I said, to invest many billions in the United States" President Trump told a packed crowd as they chanted "U-S-A, U-S-A..."

"When this plant is fully operational, hundreds of Ohio workers will have full-time jobs, with quality healthcare, retirement benefits and really great wages.....I'm especially excited to announce that 1 in 4 workers at this plant is a veteran," Trump added.

Pratt workers, scattered in the crowd and dressed in neon orange shirts, said attendance at the rally was not mandatory.

"It's a big deal," Jonathon Gay, a 28-year-old production engineer at Pratt, said of the President's visit, declining to get into politics.

The event ended a weekend that saw Mr. Trump delivering and receiving accolades from world leaders on U.S. soil, beginning on Friday when he hosted Mr. Morrison at a White House State Dinner.

Mr. Trump spent the earlier part of Sunday at a rally in Houston with Indian Prime Minister Narendra Modi that drew a crowd of 50,000 to the city's NRG Stadium. Mr. Modi touted the relationship between the two countries.

"You have never had a better friend as president than President Donald Trump," Mr. Modi said.

More than 1,000 people were transported to Pratt's sprawling campus via yellow school bus from a local high school, then waited four hours in an unconditioned warehouse for the program to begin.