Carter - who was the nation's 39th president from 1977-81 - said he would cut back "fairly dramatically" on his schedule, but did not rule out the possibility of a trip to Nepal in November.
"It's likely to show up other places in my body," he said of the illness at the nonprofit Carter Center in Atlanta, Georgia, his home state.
The former peanut farmer and ex-Georgia governor was making his first public remarks since announcing he had the disease in a brief statement this month.
"I just thought I had a few weeks left," he told the news conference, "but I was surprisingly at ease. I've had a wonderful life."
Mr Carter, who is being treated at Atlanta's Emory Healthcare, was undergoing his first treatment on Thursday.
"I'm perfectly at ease with whatever comes," he said, citing his devout Christian faith.
"I am ready for anything and looking forward to a new adventure," he added.
hope and acceptance
He said he felt "hope and acceptance", reflecting on a long career, Mr Carter continued: "I have been as blessed as any human being in the world."
"The best thing I ever did was marry Rosalynn," he added, referring to his wife of 69 years, "that's the pinnacle of my life."
The couple, who have three sons and a daughter, live in rural Plains, Georgia, about 150 miles (240 km) south of Atlanta.
Asked if he had any regrets, Mr Carter talked about the ill-fated April 1980 mission he ordered to rescue dozens of American hostages in Iran.
Operation Eagle Claw failed, and the humiliation was partly blamed for Mr Carter's landslide election defeat to Republican Ronald Reagan.
"I wish I'd sent one more helicopter to get the hostages," the one-term president said. "We would've rescued them and I would've been re-elected."
After leaving the White House, the Democrat set up the Carter Center in Atlanta in 1982 to promote democracy, healthcare and other issues.
The Nobel Peace Prize winner has written more than 20 books since leaving office.
Mr Carter is also a Baptist church deacon and a Sunday school teacher.
Source: Bloom Gist Atlanta, Sky News, BBC
Photo Credit: RT
