The injury came weeks after he injured his head in a fall at home, recovering quickly to volunteer the next day -- with a black eye and a bandage covering 14 stitches -- at a Habitat for Humanity site.

He was taken to Emory University Hospital "for a procedure to relieve pressure on his brain," The Carter Center said in a statement, adding it would take place on Tuesday morning.

"President Carter is resting comfortably, and his wife, Rosalynn, is with him," it said.

In office from 1977 to 1981, Carter placed a commitment to human rights and social justice at the core of his presidency.

He enjoyed a strong first two years, which included brokering a peace deal between Israel and Egypt dubbed the Camp David Accords.

But his administration hit numerous snags -- the most serious being the Iran hostage crisis and the disastrous failed attempt to rescue the 52 captive Americans in 1980.

His handling of the oil crisis of 1979-1980 was also sharply criticized, and images of cars lined up at gas stations were long associated with his presidency.

But as the years passed, a more nuanced image of Carter emerged that took in his post-presidential activities and reassessed his achievements.

He founded the Carter Center in 1982 to pursue his vision of world diplomacy, and he was the recipient of 2002 Nobel Peace Prize for his tireless efforts to promote social and economic justice.

In August 2015, Carter revealed he had cancer on his brain and was undergoing radiation treatment -- an illness he recovered from, seemingly against the odds. —AFP