North Korea has detained a US citizen for “rash behaviour” while passing through immigration, the official KCNA news agency has reported as President Barack Obama started a two-day visit to South Korea.

In a brief despatch, KCNA said on Friday that the American, identified as Miller Matthew Todd, 24, had been taken into custody April 10 for “his rash behaviour in the course of going through formalities for entry” into North Korea.

KCNA said he remained in detention and was under investigation.

The two-week delay in announcing the incident suggested it was timed to coincide with Obama’s visit.

North Korea is currently holding US citizen Kenneth Bae, described by a North Korean court as a militant Christian evangelist.

Bae was arrested in November 2012 and sentenced to 15 years’ hard labour on charges of seeking to topple the government.

According to KCNA, Miller had a tourist visa, but tore it to pieces and shouted that “he would seek asylum” and had come to North Korea “after choosing it as a shelter”.