Pyongyang: North Korea, on Friday, fired two unidentified projectiles into East Sea said South Korea. The nature of the projectiles is not clear yet.

The latest launch came just five days after Pyongyang fired two short range ballistic missiles, reported Yonhap News Agency.

So far, North Korea has undertaken five projectile test since July 25, likely in a show of protest against the ongoing joint military exercises between Seoul and Washington.

Meanwhile, US President Donald Trump has downplayed the testing, outlining that no part of the Singapore agreement was being violated through the launches -- a facet which was referenced in the letter.

North Korean leader Kim Jong-un also wrote a three-page letter to Trump, in which he expressed his unhappiness over the military drills.

He also offered a "small" apology for testing the short-range missiles, according to Trump. Kim reiterated that the testing would stop when the exercises end.