The Real Madrid midfielder spoke after England's 0-0 draw with Ghana in Boston — a result he assessed with characteristic candour — before warming considerably when the conversation turned to his club.
"We feel frustration," Bellingham said of the stalemate. "It is very difficult to play against teams that defend very low. It is not a drama. Calm the fans. The next game is the most important one — against Panama."
Bellingham was emphatic about his satisfaction elsewhere.
"I am very happy with the manager [Tuchel], my teammates and the supporters. My family is here and I am happy."
On Mourinho, Bellingham — who will work with the Special One for the first time when the new season begins — was immediately enthusiastic.
"Mou? Fantastic, fantastic! He is a top coach. I am very happy with him."
He was equally positive about the arrivals at the Bernabéu this summer.
"Many signings, but very good ones. Players with a lot of quality and experience. For now I am focused on England, but afterwards I am very happy with them."
Bellingham was named player of the match in the Ghana game despite his own reservations about the award, having also been caught up in a heated half-time confrontation with Ghana coach Carlos Queiroz. He scored in England's 4-2 opening win over Croatia and has been one of the tournament's most prominent players despite Tuesday's frustrating result.
Madrid have already brought in Ibrahima Konaté and Marc Cucurella this summer as Mourinho shapes his squad ahead of his second spell at the club.