In anticipation of the upcoming summit between United States President Donald Trump and North Korean leader Kim Jong-un, the White House unveiled a new commemorative challenge coin. The history of challenge coins in the U.S. military is long and full of tradition and honor.

But the summit is hardly a done deal. Kim threatened to back out last week unless the United States adjusted their expectations for the meeting. Trump is also reportedly worried about being taken advantage of by the North Korean dictator.

Kim already gained a level of legitimacy he did not have before just based on the coin design where he is referred to as "Supreme Leader Kim Jong-un" and place as an equal with Trump.

Kim has a lot to gain regardless of the outcome, either by forcing a United States leader to bow to his terms or cancelling a meeting with him. Meanwhile Trump can lose face if the meeting does or does not occur.

Despite mounting doubts about the summit actually happening, Trump's communications agency chose to publicize the new coin. If the meeting, currently scheduled for June 12 in Singapore, falls through the coin could turn into an embarrassing reminder for the president; something people are quickly pointing out.

However, this coin will not be the first stumble in the realm of challenge coins for Trump. His presidential coin design drew a lot of criticism.

Challenge coins issued by presidents began in the late 1990s with President Bill Clinton. Clinton displayed several racks of challenge coins, which had been given to him by U.S. service members, in the Oval Office. The challenge coins appear in the background of his official portrait which hangs in the White House.

Trump's coin broke with tradition, deleting the presidential seal, the motto "E pluribus unum" and the thirteen arrows representing the thirteen original states. He replaced the national motto of the United States with his own campaign slogan, "Make America Great Again", on both sides. The coin, instead of being round, featured a banner at the bottom allowing the coin to stand upright.

But what is a challenge coin? Where did the tradition come from?

A challenge coin is a coin or medallion, bearing an organization’s insignia or emblem and carried at all times by the organization’s members. Traditionally, they prove membership when challenged and enhance morale.

The exact origin is unknown, but some point to Roman times as the inspiration. From there, stories of possible origins of the tradition in the United States military come from World War I and World War II.

Challenge coins are also collected by service members or civilians working with the Department of Defense. In practice, in addition to coins owned by all members of a unit, challenge coins are presented by unit commanders, base commanders or higher ranking officials in recognition of special achievement.

Coins are exchanged between individuals in recognition of visits to an organization and special commemorative coins are created for major events.

The practice spread from active duty military to DoD civilian organizations working with the military, like the Defense Finance and Accounting Service, the commander-in-chief, high level government officials and congress. Also, some civilian organizations, such as law enforcement, now participate in the challenge coin tradition.

The White House Principal Deputy Press Secretary, Raj Shah, did issue a disclaimer for the coin, however.

Despite stating the White House had no input on the coin design, that would be highly unusual. Coins are generally designed by the organizations using them.