Pellegrini has been pleased with his goalkeeper's performances since reinstalling him as his number one.
Hart lost his place in November after a series of blunders and Costel Pantilimon took over for a spell which included seven Barclays Premier League games.
There were concerns outside the club that Hart's lack of action could affect his status with the England side but Pellegrini also wants him on song for the tournament in Brazil this summer.
The Chilean said: "For me it is very important Joe is the best performer in the national team for England, of course that's very important - and (for) Micah Richards, and (Joleon) Lescott, and every England player we have."
Hart, 26, was recalled just before Christmas and Pellegrini believes his displays since have proved the spell out did him good.
Pellegrini said: "I'm very pleased because I think we made the right decision at the right moment.
"It was very good for the team and it was very good for Joe Hart, for everyone.
"Joe Hart took it in a good way. He worked hard and came back to his normal (level of) performance."
Midfielder James Milner, although not a regular starter, has also been in fine form for City over the past month.
With Arsenal's Theo Walcott likely to miss the World Cup through injury, Pellegrini is happy to push Milner's case for inclusion.
He said: "I can't tell Roy Hodgson which are the best choices if he cannot play Walcott, but Milner is a very useful player.
"I trust a lot in him, I think he is a very good player."
Pellegrini has given no indication whether Hart or Pantilimon will play in the first leg of the Capital One Cup semi-final against West Ham on Wednesday.
Pantilimon was given another chance in the FA Cup third-round draw at Blackburn last Saturday but he made a mistake which led to Rovers' equaliser.
Pellegrini insists that will not affect his selection decision.
He said: "I don't think that because one player makes a mistake he must lose his place.
"I have a lot of different things (that dictate) why I take the decision which one will play."