Donald Trump would become the first sitting US president to meet a DPRK leader if his meeting with Kim Jong Un actually occurs.

However, Trump isn't the first US president to receive a DPRK invitation. Meanwhile, other prominent American political figures have visited Pyongyang and met DPRK leaders.

Jimmy Carter: A three-time visitor

Jimmy Carter who served as the 39th president of the US from 1977 to 1981, made a historic trip to the DPRK in June 1994.

In early 1994, the DPRK threatened to reprocess fuel rods from its nuclear reactor, which means its five or six nuclear weapons would get enough weapons-grade plutonium.

As the first former US president to visit Pyongyang, Carter's trip is believed to have defused the first DPRK nuclear crisis.

The former US president Jimmy Carter(L) meets DPRK's president of the Presidium of the Supreme People's Assembly Kim Yong Nam (R) at Mansudae Assembly Hall in Pyongyang, DPRK on Aug. 25, 2010. /VCG Photo

University of Georgia professor Han Park, who helped arrange Carter's 1994 trip, viewed it as significant as it paved the way for the negotiation of a disarmament agreement between the US and the DPRK

During the trip, Carter met with then-DPRK leader Kim Il Sung, who died three weeks after meeting with Carter and is the grandfather of current leader Kim Jong Un.

The trip was also controversial because Carter announced he had reached a deal with Kim Il Sung without checking with then-president Bill Clinton's administration.

Carter has also returned to Pyongyang twice. In 2010 he went on behalf of Aijalon Gomes, a Massachusetts resident who was sentenced to eight years of hard labor for entering the country illegally, and in 2011 he went with other world leaders to help the DPRK to assess its food crisis.

Bill Clinton manages a deal and visits in 2009

Clinton served as the 42nd US president from 1993 to 2001. He was invited by the DPRK to meet with Kim Jong Il, father of current leader Kim Jong Un but declined.

DPRK Leader Kim Jong Il (L) toasts US secretary of state Madeleine Albright at a dinner in Pyongyang on October 24, 2000. /VCG Photo

Clinton signed on to a deal known as the Agreed Framework with the DPRK in October 1994 under which the DPRK agreed to freeze the construction of two reactors which could be used to produce fuel for nuclear weapons in exchange for oil and a promise of two light-water nuclear reactors.

According to Madeleine Albright, the then secretary of state, Clinton said after receiving the invitation from the DPRK, "I am not going until this is prepared; I am sending the secretary ... That didn't thrill them."

Albright made her trip to the DPRK in 2000 and remains the highest-level US official to visit the Asian nation. When meeting with Kim Jong Il, she discussed missiles, terrorism, human rights. and other topics.

Albright's visit pushed US-DPRK relations in a positive direction.

From left, former president Bill Clinton, former vice president Al Gore, and Euna Lee look on as Laura Ling speaks at Bob Hope Airport in Burbank. Journalists Ling and Lee returned to the US after being detained for nearly five months in the DPRK on August 5, 2009. /VCG Photo

While Clinton did not visit the DPRK while in office, he visited the country in 2009 as a "private citizen." He met with Kim Jong Il to secure the release of two American journalists: Euna Lee and Laura Ling.

George Bush: Hardline policy

After taking office in 2001, George Bush took a more hardline policy to the DPRK.

He listed the DPRK as one of the three "axis of evil" nations in his 2002 State of the Union and his administration later discovered the DPRK was enriching uranium  – which the DPRK denied.

Months later, the oil shipments agreed under the Agreed Framework was suspended by the Bush administration. The DPRK ordered IAEA inspectors out of the country by the end of 2002 so that meant the Agreed Framework had collapsed.

Top US envoy Christopher Hill (L) arrives with Clark Randt (R), US ambassador to China, for round-table discussions at the resumption of Six-Party Talks, December 18, 2006, at the Diaoyutai State Guesthouse in Beijing. /VCG Photo

Bush re-engaged with the DPRK in 2003 after joining the Six-Party Talks, which included China, Russia, Japan, the Republic of Korea (ROK) and the DPRK.

Bush has also sent a personal letter to leader Kim Jong Il at the end of 2007 in which he proposed the prospect of normalized bilateral relations if Kim could keep his promise to fully disclose all nuclear programs.

Barack Obama: Strategic patience

The Obama Administration's approach to the problem of the DPRK has been termed "strategic patience."

Obama in a national security paper in 2015, officially labeled his foreign policy that "the challenges we face require strategic patience and persistence" and the strategy apparently applied to the DPRK issue.

Many described what Obama imposed on the DPRK a "failure" as DPRK's capability of nuclear weapon had advanced throughout the course of Obama administration.

His measures, which showed no major differences with previous administrations, included increased diplomatic and economic pressure but did not halt the DPRK's missile and nuclear development.

The former US president Jimmy Carter arrives in Pyongyang on August 25, 2010. /VCG Photo

Obama was open to dialogue but set a precondition of demanding the DPRK take steps towards denuclearization which left him no chances for talks with the country.

However, during his two terms, two former US presidents – Clinton and Carter – set foot on the soil of the country and engaged with DPRK officials on returning jailed US citizens.

Donald Trump: A battle of words

Tensions between the DPRK and the US have been highlighted with a growing number of nuclear tests – seven times from February to November – from the DPRK in 2017, while Trump warned the country of "maximum pressure and engagement."

The countries have exchanged a fierce "war of words" since the inauguration of Donald Trump in January last year.

The interaction between the two countries seems to follow a pattern – a provocation, unilateral or UN sanctions and exchanges of insults between Trump and Kim Jong Un, the leader of the DPRK.

Words like "madman", "fire and fury" and "rocket man" have been often used by Trump when referring to the DPRK leader.

Kim has used threats to "sink Japan," turn the US to "ashes and darkness" and refer to Trump as a "dotard." 

The battle of words had been escalating and Trump made a speech at the UN general assembly on September 19 threatening to "totally destroy" the country.

"If forced to defend ourselves or our allies, we will have no choice but to totally destroy North Korea (DPRK)," he said. "Rocket Man is on a suicide mission for himself and for his regime."

AMunhwa Ilbo newspaper featuring US President Donald Trump and the DPRK leader Kim Jong Un on the front page is displayed for sale at a newsstand in Seoul on Friday, March 9, 2018. /VCG Photo

Kim responded via the country's state media, using the word "dotard" to describe the US president – referring him as old or weak.

"Kim Jong Un of North Korea (DPRK), who is obviously a madman who doesn't mind starving or killing his people, will be tested like never before!" Trump said in reaction to the "dotard" comment.

Moving into 2018, the tensions on the Korean Peninsula have eased as the DPRK leader extended an olive branch to the Republic of Korea (ROK) in his New Year speech.

The DPRK then agreed to send athletes and high-level delegations to the PyeongChang Winter Olympics. Two groups of US high-profile officials were also sent to the Games. However, the two sides did not have any interactions.

Now all eyes are on the proposed summit between the two leaders as Trump accepted Kim's invitation but said "sanctions will remain" until a deal is reached.