SEOUL, Nov 18 (AFP) - North Korea fired at least one ballistic missile, South Korea's military said on Friday, its second missile launch in as many days.

South Korea's Joint Chiefs of Staff reported the launch but did not immediately elaborate on the type or range of the missile.

A day earlier, North Korea fired a ballistic missile while it warned of "fiercer military responses" to U.S. efforts to boost its security presence in the region with its allies, saying Washington was taking a "gamble it will regret".

This year North Korea has conducted a record number of such tests, which are banned by United Nations Security Council resolutions that have sanctioned the country over its missile and nuclear weapons programmes.

The North has also fired hundreds of artillery shells into the sea recently as South Korea and the United States staged exercises, some of which involved Japan.