ABC News March 17, 2016

Past Cases May Indicate Likelihood of US Student's Release by North Korea

WATCH: Diplomatic Battle to Get American Student Back From North Korea

While efforts to free Otto Warmbier, a U.S. student who was sentenced to 15 years hard labor in North Korea after attempting to steal a propaganda poster, are underway, history suggests that the odds of his being released are in his favor.

The Associated Press has identified at least seven Americans who have been held and then released from North Korean detention. An eighth, Sandra Suh, is still being held after being detained in April 2015, as she stands accused of making anti-North Korean propaganda during her visit, according to the AP.

The involvement of U.S. government officials seems to be a common theme in the release of Americans.

At least three Americans -- a student and two men who were held for perceived missionary activities -- were released from detention in North Korea in 2014. The AP reported that Director of National Intelligence James Clapper intervened and flew to Pyongyang to bring them home.

Jae C. Hong/AP Photo
Euna Lee, left, and Laura Ling, two American journalists who were arrested in March after allegedly crossing into North Korea from China, are greeted after the two arrive at Bob Hope Airport in Burbank, Calif., Aug. 5, 2009.

In 2009, two journalists were released after former President Bill Clinton traveled to the country as part of the deal.

Work is already underway to try to get Warmbier, a 21-year-old University of Virginia student, released, but the exact details about the process are being kept under wraps.

White House Urges North Korea to Release American Tourist What We Know About the American Student Held in North Korea

Bill Richardson will likely be among the key players in whatever negotiations take place to free Warmbier. The former New Mexico governor served as the American ambassador to the United Nations.

Richardson said he made contact with North Korean diplomats at the United Nations at the urging of Warmbier's parents, who live in Ohio, and their state's governor, Republican presidential candidate John Kasich.

"He did a college prank, a mistake, but 15 years to be sentenced. That's crazy," Richardson said. "Hopefully now after this sentencing, it'll mean negotiations can start on his release on humanitarian grounds."

Kyodo/AP Photo
U.S. missionary Robert Park, who has been detained in North Korea since December, arrived at Beijing Capital International Airport from Pyongyang on Feb. 6, 2010, a day after North Korea said he would be released because he has reflected on his act and offered apologies.

Warmbier was found guilty of subversion after taking a propaganda poster from a restricted area in the hotel where he had been staying during a group trip to the country.

Americans are legally allowed to travel to North Korea, but the state department "strong recommends against" it.

The State Department warns on its travel warning page that "U.S. citizens to North Korea is not routine, and U.S. citizens have been subject to arrest and long-term detention for actions that would not be cause for arrest in the United States or other countries."

AFP/Getty Images
Former New Mexico Governor Bill Richardson speaks to the media at Beijing International airport in Beijing, Jan. 7, 2013, before his trip to North Korea.

White House spokesman Josh Earnest said Wednesday it is becoming increasingly clear that the North Koreans see the arrest and detention of an American as a bargaining opportunity.

"Despite official claims that U.S. citizens arrested in North Korea are not used for political purposes,” he said, “it is increasingly clear that the North Korean government seeks to use these U.S. citizens as pawns to pursue a political agenda.”