Earlier speculation suggested it may have had something to do with marking the birthday of the deceased founder of the country.
North Korea celebrates its founder's birthday on Saturday and has tested missiles on significant occasions in the past.
President Donald Trump has sent a Naval strike group toward the Korean Peninsula as the threat of a North Korean nuclear test looms.
North Korea's Asian Cup tie with Malaysia has been postponed.
China said that international action should wait until the investigation is complete.
A man claiming to be Kim Han Sol released a video saying that he is in hiding with his mother and sister.
Malaysian police investigating the murder of Kim Jong Nam questioned up to three men hiding in the North Korean embassy.
Regional stakes high given North Korea's threat to test an intercontinental ballistic missile.
Pyongyang's main newspaper said Barack Obama's "strategic patience" had not paid off.
North Korea is preparing to fight a nuclear war in the Korean peninsula against the USA and its allies.
Friday's test was confirmed after reportedly causing a 5.3 magnitude earthquake.
Pyongyang has warned against a U.S.-South Korea military drill.
The U.S. decision to deploy the THAAD system comes after Pyongyang's recent nuclear and missile tests.
The site is the source of plutonium for the country's nuclear weapons program.
The North Korean leader has also banned freedom of movement in the country as security tightens.
The isolated nation has conducted a series of missile launches ahead of the Workers' Party congress on May 6.
The North Korea rocket crashed just moments after takeoff.
North Korea's growing gray market economy is posing a problem for Kim Jong Un and company.
North Korea failed to launch a ballistic missile off the country's east coast.