North Korea lambasted South Korea and the United States on Saturday for staging a joint air exercise, accusing Washington of driving the Korean Peninsula into an "uncontrollable" situation.

The Freedom Flag exercise kicked off this week to run through next Friday, with the air forces of South Korea and the US, as well as Australia, participating.

The two-week joint drill, which is taking place for the first time, replaces regular large-scale air exercises between South Korea and the US -- Korea Flying Training in the first half of the year and Vigilant Defense in the second half.

In a statement carried by the Korean Central News Agency, an official at the North's foreign ministry said Freedom Flag is a "very dangerous act of military provocation" aimed at launching a "preemptive" and "unexpected" strike on North Korea.

Pyongyang accused the US of encouraging South Korea's "hostile lunacy" by supporting its sending of propaganda leaflets to the North and continuing to deploy strategic assets on the Korean Peninsula.

The US is driving the peninsula into an "uncontrollable" situation, and "if a situation no one wants takes place, the US would have to take full responsibility for it as the prime mover that aggravated tensions in the region," the statement read.