Sterling started six matches as Gareth Southgate's men finished fourth at the 2018 World Cup and has scored twice in three Premier League starts for the reigning champions this term.
A back complaint ruled the 23-year-old winger out of the double-header but Guardiola confirmed he has the all-clear for Fulham's visit to the Etihad Stadium on Saturday.
"He's fit. In the last days [in training] he has been better," the City boss told a pre-match news conference.
Sterling is into the final two years of his contract in Manchester and Guardiola reiterated his desire to tie the former Liverpool winger to a long-term deal.
However, he conceded the final decision regarding the future of a player who was recently linked to Real Madrid is out of his hands.
"It's well known that we are delighted with him and want him to continue," Guardiola added.
"The club asked me my opinion about that, we shared that. And after that it is the club and Raheem's agent. I am outside. I am not involved.
"Sometimes this kind of thing needs its own time. The important thing is Raheem and his people know how delighted we are with him.
"After that maybe it will happen, maybe not."