"At the end of the Olympics and Paralympics, it’s only natural that our routine defensive exercises will resume," the official said on Tuesday.
In early January, US President Donald Trump and South Korean President Moon Jae-in reached an agreement to halt joint military exercises during the Winter Olympic Games in Pyeongchang.
The UN Security Council has introduced multiple rounds of sanctions against North Korea aimed at hampering the development of the country’s nuclear program.
Meanwhile, Seoul and Pyongyang earlier reached a historic agreement on holding the third ever summit of the countries’ leaders in late April. US Vice President Mike Pence however ruled out on Tuesday any change in US' firm position on North Korea until Pyongyang takes concrete steps to give up its nuclear programme.