In a tweet from his first foreign trip as president, President Donald Trump touted his accomplishments on one of the cornerstones of his presidential campaign -- jobs.

Trump traveled to Saudi Arabia, Israel, Brussels and Rome on a mix of business and diplomatic tasks from May 20 to May 27.

"Just arrived in Italy for the G7. Trip has been very successful. We made and saved the USA many billions of dollars and millions of jobs," Trump tweeted.

Just arrived in Italy for the G7. Trip has been very successful. We made and saved the USA many billions of dollars and millions of jobs. — Donald J. Trump (@realDonaldTrump) May 26, 2017

Millions of jobs? That would be a massive shot in the arm for the economy. For a sense of scale, Wal-Mart, the nation’s largest private employer, has 2.3 million employees; the second-largest, Yum Brands, which includes Taco Bell, Pizza Hut and KFC, has about 500,000.

The problem is, the White House has been cagey about exactly where this projection comes from.

For starters, Trump’s use of the word "millions" represents a thousand-fold expansion from what Trump had said just days earlier, when he told the audience in a speech in Saudi Arabia: "Yesterday, we signed historic agreements with the Kingdom that will invest almost $400 billion in our two countries and create many thousands of jobs in America and Saudi Arabia."

Meanwhile, over two days of inquiries to the White House, officials were unable to provide us with full details of the $110 billion arms deal with Saudi Arabia, which itself is just a portion of the $400 billion investment package Trump cited in his speech.

When the Washington Post Fact Checker asked the White House for details about Trump’s tweet, a White House official responded that Trump was referring to "benefits to trade from the entire trip from Saudi Arabia to the G7" -- that is, including Trump’s meetings with the heads of other advanced industrialized nations in Europe toward the end of the trip. (It’s not clear what trade deals were discussed in the European portion of the trip.)

In any case, assuming "millions" of jobs from unspecified investments is not justified, economists say.

"There’s not enough information to substantiate his claims on millions of jobs," said Chris Lafakis, senior economist at Moody’s.

In the meantime, here’s what we know and don’t know.

The arms deal

The Defense Security Cooperation Agency issued a news release on May 20 saying that the United States and Saudi Arabia agreed to a $110 billion package on five main areas: border security and counterterrorism, maritime and coastal security, air force modernization, air and missile defense, and cybersecurity and communications upgrades.

The release detailed six specific areas, with links to documents that offered a dollar amount. They were:

• Munitions and support: $6.8 billion;

• Multi-Mission Surface Combatant ships: $11.25 billion;

• Ammunition for the Royal Saudi Land Forces: $500 million;

• Saudi Abrams Main Battle Tanks and HERCULES Armored Recovery Vehicles: $1.15 billion;

• Chinook cargo helicopters: $3.51 billion;

• Persistent Threat Detection System Aerostats: $525 million.

That totals $23.74 billion, leaving $86 billion from the package unspecified.

Using other available data, John Pike, the director of globalsecurity.org, told PolitiFact that he can estimate perhaps $50 billion in arms sales, "most of which was initiated under Obama," he said.

Bloomberg calculations

Reporters at Bloomberg have written several articles about the deals signed in the Saudi portion of the trip, focusing on agreements outside the $110 billion arms deal.

They include:

• Agreements signed by Saudi oil company Aramco: $50 billion;

• Commitments by Saudi Arabia’s Public Investment Fund to an infrastructure investment fund with the Blackstone Group. (Blackstone, Bloomberg reported separately, has close ties to the family of Trump’s son-in-law, Jared Kushner.) $20 billion;

• General Electric memorandum of understanding with Saudi Arabia: $15 billion;

• Honeywell International memorandum of understanding with Saudi Aramco: $3.6 billion;

• McDermott International memorandum of understanding with Saudi Aramco: $2.8 billion;

• Jacobs Engineering Group memorandum of understanding: $250 million;

• Rowan Companies memorandum of understanding with Saudi Aramco for offshore drilling rigs: $7 billion;

• Rowan memorandum of understanding with Saudi Aramco for its supply chain: $1.2 billion;

• Nabors Industries memorandum of understanding on well and rig services on an existing joint venture worth $9 billion;

• Nabors memorandum of understanding with Saudi Aramco for its supply chain: $1.6 billion;

• Weatherford International memorandum of understanding: potential value of $2 billion.

That works out to about $112 billion, coming on top of the $110 billion in arms sales. Bloomberg cited a few more items without specific dollar amounts, including a jet purchase from Boeing by SaudiGulf Airlines, and a joint venture between National Oilwell Varco and Saudi Aramco for the manufacture of drilling rigs and equipment.

That leaves more than half of Trump’s $400 billion figure -- just for the Saudi leg of the trip -- undisclosed, to say nothing of what deals may have been struck in the European portion of the trip.

And for now, the Washington Post reported that several key CEOs of companies that signed deals have been a lot more restrained than Trump about promising specific numbers of jobs.

"There is absolutely zero chance that the trip created millions of jobs," said Dean Baker, a liberal economist. Even if jobs were created -- possibly in the thousands, not the millions -- "this may or may not lead to any net job creation, since the Fed could easily offset it with higher interest rates."

Our ruling

Trump said that deals struck on his first foreign trip as president created and saved "millions of jobs."

We can’t know for sure how many jobs will be created or saved -- nor, despite the certainty of his language, does Trump -- but the evidence at this point is so thin and so premature as to be little more than puffery or wishful thinking. We rate the statement False.