Such trips are not unusual for Carter, 86, who in the three decades since he left office has often mediated, on an unofficial level, with pariah states.
In 2002, he became the first U.S. president to visit Cuba since its 1959 revolution. He's traveled to a number of other world hot spots, including Gaza in 2009, where he met with the then-leader of the U.S. designated terrorist group Hamas.
Carter is "unorthodox in his approach. What was once unorthodox has become the Carter orthodox, so going to Cuba right now is not surprising," said author and history professor Douglas Brinkley, who traveled with Carter to Haiti in the early 1990's. "His bully pulpit is the globe, not the White House. He's erased what they think about his track to diplomacy."
It's "Jimmy Carter going by the beat of his own drum," he added. "There are times that he raises eyebrows and it's all part and parcel of Carter's post-presidency. You can't really cherry pick them."
Though Carter has been mum on the issue of jailed U.S. government contractor Alan Gross, his release is likely to be a central topic of discussion in the former president's meeting with President Raul Castro, who invited Carter to Cuba.
Gross was arrested in 2009 in Cuba and was sentenced this month to 15 years for illegally bringing in telecommunications equipment and for crimes against state security.
Carter, a prominent figure on the international stage known for his diplomacy, traveled to Pyongyang in August 2010 to retrieve an American citizen, Aijalon Mahli Gomes, who had been sentenced to eight years in prison for entering North Korea illegally from China that January.
While his efforts may not be as visible as those of former President Bill Clinton, those who follow his work say Carter has been more successful in this arena than any of his peers.
It could be days before Gross is on his way back home because of Carter's trip, Brinkley says.
"Carter has an extraordinary record, as ex-president of getting political prisoners released," Brinkley said. "I would expect that Gross will be out because... Carter's bringing the prestige towards the Cuban government that they're looking for out of an American figure of his stature."
Carter today said he spoke to Cuban officials about Gross but added, "I am not here to take him out of the country. ... We are here to visit the Cubans, the heads of government and private citizens."
Carter rarely travels as an official envoy, or with an official delegation, of the U.S. government, unlike Clinton. Of his upcoming North Korea trip, the State Department said they had not had any contact with Carter about it except to be informed of the trip.
His unorthodox style and rogue trips have often resulted in a clash with U.S. administrations.
In 1994, he went to Haiti just as Clinton was preparing to launch an attack against the island nation. Carter also clashed with the Bush administration, specifically Vice President Dick Cheney, whom he dubbed a "militant" in foreign policy.
The Obama administration has been so far mostly mum on Carter's ventures, but observers say his untraditional approach can be challenging.
"It's sort of a welcomed nuisance by each of these administrations," said Russell Riley, a presidential scholar at the University of Virginia Miller Center of Public Affairs. "President Carter's interventions have been useful but by the same token, if you're working in the White House and you're trying to choreograph a relationship with very difficult authoritarian regimes, having another independent actor in the mix can be as frustrating as it is helpful."
Carter is not the only former living president to be involved in international affairs. Clinton has been actively involved in world affairs, specifically relief efforts in Asia after the 2005 tsunami and in Haiti after the earthquake there last year. Former President George H.W. Bush has also been active in relief efforts in both countries, as has his son to a lesser extent.
But Carter doesn't enjoy the same kind of celebrity status as Clinton and observers say most of his work has been under the radar.
Carter, the least popular post-war president when ranked by job approval rating, has since then gained respect both on the global scale and domestically for his humanitarian work through the Carter Center. He's also faced his share of controversy, especially in advocating for Palestinians.
"This was a man who created enormous opportunities for himself after he left the White House as kind of a rejected political figure in 1980. And so in some respects what you see from President Clinton is, whether self-consciously or not, modeled after what President Carter has done," Riley said.