Gulati said 60 of the tournament's matches would be staged in the United States, with Canada and Mexico hosting 10 games each. The United States would host all knockout games from the quarter-finals onwards, he added.
He played down the possibility that politics could hamper the bid, emphasising that Trump was "especially pleased" with Mexico's involvement.
"The president of the US is fully supportive... We are not at all concerned at some of the concerns that some people may raise," Gulati said.
Trump was elected last year after a campaign marked by rhetoric against Mexico, vowing to build a wall to keep out illegal immigrants he branded "criminals" and "rapists."
The joint bid will start as the heavy early favourite in the race, despite United States prosecutors leading the probe into football corruption which rocked the sport in 2015 and led to the downfall of former FIFA supremo Sepp Blatter.
A bid from the North America region for 2026 had long been regarded as inevitable by FIFA watchers.
That sense of certainty hardened last year, when FIFA's council ruled that neither Europe nor Asia would be eligible to run for the 2026 tournament on the grounds that the regions are hosting the next two World Cups. Russia is hosting the 2018 finals, followed by Qatar in 2022.
With Europe and Asia ineligible, CONCACAF could in theory face potential competition from the Africa, South America and Oceania regional confederations.
US soccer officials had been publicly coy about the possibility of a future World Cup bid since the country lost out to Qatar in the battle for the 2022 tournament at a corruption-tarnished vote in Zurich in 2010.
However the prospect of a fresh American bid gathered momentum in 2014 after the World Cup in Brazil.
That campaign captured the imagination of US sports fans, with huge crowds attending public screenings of games at cities across the country.
The country's club game is also booming, with record numbers attending Major League Soccer games in 2016.
The United States also burnished its credentials as a major tournament host with last year's 16-team Copa America Centenario.
The United States first hosted the World Cup in 1994, staging a commercially successful 24-team tournament that played out to packed stadia.
The 1994 tournament remains the most attended World Cup in history, with just over 3.5 million fans flocking to its 52 games, an average of 68,991 per match.
Mexico has hosted the World Cup twice before -- the 1970 finals won by a Pele-inspired Brazil and the 1986 tournament won by an Argentina team led by Diego Maradona.
Canada, who have only made one World Cup appearance when they were eliminated in the first round of the 1986 finals, has never hosted the tournament.
However Canada earned plaudits for its staging of the Womens' World Cup in 2015, which was won by the United States in the final in Vancouver.
Under FIFA plans for its expanded 48-team World Cup, CONCACAF is awarded six berths. Gulati indicated that officials expected all three host nations to be granted places.
"There has never been a World Cup where the host countries have not been qualified," Gulati said.
A tournament in North America is also likely to be attractive to FIFA for solid public relations reasons.
With dozens of modern, tournament-ready venues to choose from, there is little risk of stadiums being left to rot as white elephants following the event, a problem which has embroiled grounds used at the 2010 and 2014 World Cups.
"We have the luxury of having stadiums that already exist," Gulati stated.