US South Korea
US South KoreaReuters

South Korea and the United States on Saturday concluded their biggest joint military drill, which had sparked angry reactions and threats from North Korea over the past two months. While Pyongyang has carried out several missile tests in defiance of United Nations sanctions, it is now also said to be readying for its fifth nuclear test, which South Korean media said could be carried out next week. 

The annual joint military drill between the two allies came just months after North Korea carried out a nuclear test in January, for which it was slapped with heavy sanctions by the United Nations. The exercise saw 300,000 South Korean armed forces and 17,000 U.S. forces participate, as well as the  deployment of the American nuclear-propelled aircraft carrier USS John C. Stennis (CVN-74) and two Wasp-class amphibious assault vessels, according to Yonhap News Agency

While the outdoor training programs had been ended on Friday, the military assets and troops of the two countries were withdrawn on Saturday, according to the report. 

North Korea issued several threats to Seoul and Washington over the joint drill, even threatening nuclear strikes. The Kim Jong Un regime later even made an offer to the United States of suspending nuclear tests if the latter stopped the joint drills with South Korea. U.S. President Barack Obama, however, dismissed Pyongyang's assurances

According to South Korea's military, North Korea is now set to carry out its fifth nuclear test ahead of a rare ruling party meet called on May 6, the first in 36 years, Yonhap reported. 

"North Korea appears to have finished preparations (for the atomic test)," Seoul Defense Ministry spokesman Moon Sang-gyun reportedly said on Friday.