(CNN)North Korea attempted a missile launch Tuesday at 5:20 a.m., but it is assumed to have failed, South Korea's Joint Chiefs of Staff said.

It appears to be the latest in a string of missile tests as the country tries to advance its weapons program in defiance of the international community and its closest regional ally, China.

The last several months have been particularly contentious, after North Korea claimed to have tested its first hydrogen bomb and fired a satellite into orbit.

Both actions violated numerous United Nations Security Council resolutions.

In April, North Korea fired two midrange Musudan missiles, although both appeared to be unsuccessful.

North Korean missile launch attempt apparently failed, South Korea says - CNN.com