LATEST: Ex-president George HW Bush remains in Houston Hospital

A family spokesperson says the 92-year-old "is going to be fine" and is already recovering.

UPDATE 5.30pm: Former President George HW Bush is under observation at a Houston hospital after recovering from "a mild case of pneumonia".

Family spokesman Jim McGrath said on Wednesday that the 92-year-old "continues to gain strength ... had a good night's rest, and his spirits are high".