England had led through Anthony Gordon's second-half opener before Argentina scored twice in the space of seven minutes late on to complete a stunning turnaround, ending the Three Lions' hopes of a first World Cup final appearance since 1966.
Tuchel was criticised in some quarters for a series of defensive substitutions as England sat deeper in search of the win, but FA chief executive Mark Bullingham made clear the governing body's support for the head coach remains unwavering.
"It is heartbreaking to be so close," Bullingham said. "The players and Thomas gave it everything today and the squad, coaches and staff could not have worked harder during the tournament.
"I would like to thank them all - and also give my heartfelt thanks to our wonderful fans here in the USA and at home."
Tuchel signed a two-year contract extension in February, having originally been appointed in January 2025 on an 18-month mission to win the World Cup. The 2028 European Championship finals are being co-hosted by England, Wales, Scotland and the Republic of Ireland, and Tuchel has previously spoken of leading a home Euros as a rare opportunity he is keen to embrace.
Speaking at his post-match news conference in Atlanta, the German said his focus was already turning towards that assignment despite the pain of Wednesday's defeat.
"We keep on going with the contract until the home Euros. I'm looking forward to that even though right now it's difficult to look that far ahead," Tuchel said. "Of course, it's a semi-final; a lot of big football nations are eliminated before the semi-final, so it is an achievement. No-one wants to hear that at the moment; me neither because we demand the most of ourselves. That's just the nature of being competitive."
Despite the disappointment of Wednesday's result, England's progress to the last four will be viewed internally as a relative success, representing their best World Cup showing since they won the tournament on home soil in 1966. Victory over France in Saturday's third-place play-off would extend that best finish further still, with Tuchel now set to turn his attention to rebuilding the squad ahead of the qualification campaign for the 2028 tournament.
England's run to the semi-final featured notable results against fellow contenders, and Bullingham's public backing removes any immediate uncertainty over the manager's position heading into a period that would typically invite scrutiny following a major tournament exit. With the next assignment being a home tournament, the FA is understood to view continuity as central to its planning, having already committed to Tuchel beyond the World Cup regardless of the outcome in the United States.