South Korea's presidential office said on Friday U.S. President Barack Obama had indicated he would take every action under a mutual defense treaty with the South, including providing its nuclear umbrella, to protect Seoul from any North Korean threat.

Obama and South Korean President Park Geun-hye talked by telephone, South Korea's Blue House said, after a seismic event was recorded in North Korea that Seoul and Tokyo described as a nuclear test. [nL3N1BL174]

South Korea's presidential office said the two leaders agreed to use every available means to pressure North Korea to abandon its nuclear program, including adopting a new U.N. Security Council resolution.