South Korea's military has not yet determined the details of the short-range projectiles that North Korea fired last week.

A military official said on Sunday that South Korea and the U.S. are conducting joint assessment and joint analysis, adding they are not at a stage yet where they can say when the results will be coming. 

North Korea test-fired multiple projectiles and at least one tactical guided weapon on May fourth and launched two short-range projectiles similar to the new tactical weapon five days later.

Experts have said North Korea appears to have test-fired a modified version of Russia's Iskander ballistic missile which usually flies as far as 500 kilometers. 

However, the South Korean military remains cautious that it cannot confirm the projectiles were Iskanders just by their similar appearances.