TOKYO -- U.S. President Donald Trump could become the first sitting U.S. president to visit North Korea if plans for a summit with Kim Jong Un hold. But other prominent American political figures have visited Pyongyang, North Korea's capital, in the past, many with a similar goal of trying to stop its nuclear program.

CARTER'S HISTORIC FIRST

Jimmy Carter made history as the first former U.S. president to visit North Korea in June 1994. Carter's unofficial four-day visit included a meeting with then-North Korean leader Kim Il Sung, the grandfather of current leader Kim Jong Un. His intervention headed off a potential conflict and helped seal an aid-for-disarmament agreement that lasted nearly a decade.

U.S. Secretary of State Madeleine Albright

THAWING TENSION

Madeleine Albright is the highest-level U.S. official to visit North Korea while in office. As secretary of state, she met in October 2000 with leader Kim Jong Il, the father of the current leader. They discussed topics from missiles and terrorism to human rights. Albright's visit pushed U.S.-North Korea relations in a positive direction.

Bill Clinton meets with North Korea's Kim Jong Il

CLINTON'S SURPRISE

On August 4, 2009, former President Bill Clinton arrived unannounced in North Korea on a mission to free two detained American journalists, Laura Ling and Euna Lee. His visit came at a time when tensions were high over North Korea's nuclear program. Then-leader Kim Jong Il granted a "special pardon," freeing the two jailed journalists after he and Clinton held talks.

Former U.S. President Jimmy Carter

CARTER RETURNS -- TWICE

Carter returned in August 2010 to bring home a jailed Bostonian, Aijalon Gomes, who had entered the communist country illegally from China. He had been sentenced to eight years of hard labour in prison. In April 2011, Carter arrived in Pyongyang again, this time with other former world leaders to discuss a food shortage in the country and to try to restart talks to persuade North Korea to abandon its nuclear ambitions.

U.S. special envoy Joseph Yun

OTTO WARMBIER

Most recently, Joseph Yun, then the U.S. special representative for North Korea policy, travelled to North Korea in June 2017 to try to bring home an imprisoned American college student, Otto Warmbier. Yun was able to secure Warmbier's release, but he was comatose and died shortly after his return to America.