Gowon made the call while speaking with State House correspondents shortly after meeting behind closed doors with Buhari at the Presidential Villa, Abuja.
The former military leader noted that a lot of national problems cropped up daily that God needed to give the President the strength to deal with.
He said, “I am also here to encourage him (the President) to continue to do his work to the best of his ability, dealing with all the problems.
“Day in day out, you read in the press of all sorts of things happening in the country.
“God will give him (the President) continued strength and energy to deal with the problems of the country for the good of Nigerians.
“I am delighted to be here, to welcome him back and to see him in reasonably good health and able to do whatever he is able to do.”
Gowon said he was at the Presidential Villa to welcome Buhari back from his medical vacation and to thank God for restoring his health to enable to him return to work.
The former military leader added that he also thanked the President for consoling him on the telephone when he lost his sister.
He added, “The other thing also is to thank him very much indeed for ringing me when he was in London to commiserate with me on the death my sister.
“That was really very gracious of him. I should have rang to speak to him but of course, since I know that he was in hospital, I could not do that.
“But when he rang to condole with me on my sister’s death, I was very touched and that also helped Nigerians to rejoice, especially those who were sending all those very unfortunate messages about him and about whatever it was.”