Retired NBA star Dennis Rodman has reportedly landed in North Korea to shoot footage for a TV show set to air on HBO in April, and will engage in "basketball diplomacy" in the country by running a sports camp for children and playing games with local basketball fans.

The former NBA star's trip has been described as an "odd choice" by some observers, as his "sports diplomacy" comes at a time of heightened tensions between the US and North Korea, after the latter carried out an underground nuclear test earlier this month. The US State Department said it was not informed of Rodman's trip in advance.

This is the second high-profile private visit by Americans this year to North Korea. In January, Google executive chairman Eric Schmidt and former New Mexico governor Bill Richardson visited Pyongyang.

Some analysts believe that such private trips have some kind of "political aspect," as the North is under intense international criticism for threatening regional security. There are channels to keep the official communication between the US and North Korea open, but Washington has been strongly against having direct bilateral talks with Pyongyang.

The visits of American public figures to North Korea must have been authorized by the Pyongyang's leadership. The olive branch of person-to-person diplomacy it sent to the US shows the country's willingness to open a non-traditional channel for communications with the US government.

The function of person-to-person diplomacy has been proved in diplomatic practice in the development path of bilateral relations. Ping-Pong Diplomacy, which heralded the establishment of diplomatic ties between the US and China, is among the most well-known examples.

Another example exists in the relations between the South and North Koreas when the sport of table tennis brought the two into one in 1991. Although the relations between the two sides were at a low point at that time, the "unified Korea" team managed to beat long-time champion China, which greatly inspired Koreans worldwide. The story was made into a film in 2011.

As in other parts of the world, basketball is exploding in popularity in North Korea. Hopefully the North will show no surprise over Rodman's piercings on his lower lip and the maze of tattoos on his chest.

The gradual opening-up of North Korea will help it better communicate with the international community. A cold US-North Korea relationship will do no good for regional security. Communication between the two countries should be the trend, which began from person-to-person diplomacy.