DIA, event organizers paid for Mayor Mike Johnston's trips to Paris, Ireland

Denver Mayor Mike Johnston has been hopscotching to European cities practically free of charge, his office confirmed.

Event organizers picked up Johnston's expenses for his trip to France, while Denver International Airport paid for his trip to Ireland.

Because organizers paid for much of those expenses, it's not clear what they ultimately cost.

Johnston's trip to Dublin on May 18 to celebrate the opening of Aer Lingus’s first non-stop flight from Denver to Ireland, cost roughly $8,000. The flight itself was $3,680.90, while food and lodging came in at $4,000.

But Denver International Airport picked up all of that tab.

A delegation of nearly 50 people, representing various city agencies and Denver companies, accompanied Johnston to Dublin. Officials said the trip was aimed at deepening Denver’s ties with Ireland. The city has signed roughly $1.2 billion worth of contracts with Irish companies in the past five years, according to previous reports.

Some 50 years ago, Robert Briscoe, the mayor of Dublin, came to Denver in 1962 and was reportedly inspired by the revival of Denver’s St. Patrick’s Day Parade.

Johnston went to Boston on June 9 to "discuss key issues like affordable housing, adaptive reuse, downtown vibrancy, climate resiliency, and building a family-friendly city," according to a release announcing the trip.

"Great to be in Boston talking with @mayorwu about our shared goals for housing, public safety and building family-friendly cities," he said on Instagram.

The mayor’s office said it paid $328.90 for a one-way trip to Titletown, with other costs covered by organizers.

Johnston also made a surprise trip to Detroit to watch the 2024 NFL Draft and discuss entering a bid for Denver to host the event in the future.

"I want to see the NFL draft in Denver one day," he said in an Instagram post. "It would put millions into our local economy, and let us show off how vibrant our city really is!"

Members of the city delegation went as guests of the NFL Draft Committee and the trip was not paid for with city money, the mayor's office earlier said.

Johnston traveled to Paris on June 21 to speak at a homelessness conference.

The mayor's office said the trip cost city taxpayers zero, as event organizers covered all costs.

Travel by Denver mayors to other cities or countries, to ostensibly explore or attract development to the city, are not new.

In 2022, then-Mayor Michael Hancock's trip to Egypt and Ethiopia cost more than $100,000. The airport also covered a majority of that trip, while taxpayers paid for $20,000.

Hancock's trip to Ireland, the United Kingdom and Turkey cost $66,000, with taxpayers on the hook for more than $15,000. Again, the airport covered the rest of the costs.

Hancock also traveled to Japan and Australia and New Zealand, costing taxpayers a further $102,000, according to published reports.