Former US president George H.W. Bush was being treated for a blood infection on Tuesday after being admitted to a Texas hospital shortly after the funeral of his wife, Barbara.
President Donald Trump wished the 93-year-old former president a "very speedy recovery" as he welcomed French leader Emmanuel Macron to the White House.
Bush's office said he was "responding to treatments and appears to be recovering" after "contracting an infection that spread to his blood."
A family spokesman, Jim McGrath, told CNN that Bush was awake, alert and talking.
The 41st president was admitted to Houston Methodist Hospital on Sunday morning, the day after the memorial service in the Texas city of his wife of 73 years.
Barbara Bush died on April 17 at the age of 92.
George H.W.Bush attended the funeral along with three other former presidents, his son, George W. Bush, Bill Clinton and Barack Obama.
Bush, who suffers from Parkinson's disease and is wheelchair-bound, has been hospitalized on several occasions in recent years, including for pneumonia.
A former congressman, US ambassador and CIA director, Bush served as vice president to Ronald Reagan for eight years after losing the 1980 Republican primary.
He was elected president in 1988, but served only one term, defeated by Democrat Clinton in 1992.
After retiring from public life, Bush joined Clinton to raise funds for victims of the 2004 Asian tsunami and the 2010 Haiti earthquake.
In February 2011, Obama awarded Bush the highest US civilian honor, the Medal of Freedom.