Despite strained North Korea-U.S. relations, the number of North Koreans who visited the U.S. in the year's first half grew over 50 percent year-on-year.

This is according to Radio Free Asia, which cited immigration data by the Department of Homeland Security.

The report says that 89 North Koreans visited the U.S. in the first half of last year, which rose to 139 in the same period this year. It took note of brisk bilateral civic exchange.

A delegation of scientists visited the U.S. from North Korea in February followed by an economic delegation's visit in March.

In early June, a group of 17 North Koreans showcased performances of the Korean martial art taekwondo in three eastern U.S. states. Delegates from the North's Korean Central News Agency also visited the U.S. in mid-June and met with officials of the Associated Press to discuss opening an AP branch in Pyongyang.

Radio Free Asia says the North Koreans who visited America were typically issued a three-month nonimmigrant visa for tourism, study or investment by the U.S. State Department.