North Korea has called on the United States not to side with South Korea over the findings of a probe into three drones found crashed near the inter-Korean border.

The North's army mission at the border village of Panmunjom on Sunday accused the U.S. of echoing South Korea's conclusion that North Korea is behind the rudimentary drones that were found in the South in recent weeks.

"If Washington pays heed only to what its stooges trumpet, it is bound to be accused of being a senile grandfather trying to stop a child from crying," the army mission said in a statement carried by the North's official Korean Central News Agency on Monday.

The statement came just days after South Korea said that the three drones were all sent from North Korea, citing an analysis of geographical data retrieved from the spy aircraft.

A team of South Korean and American experts confirmed the origin of the drones after restoring the coordinates of the GPS stored in their systems, according to South Korea's defense ministry.

Still, the North flatly denied its responsibility.

"We clarify once again, the story about the 'north's involvement' in the 'drone case' is nothing but a 'charade' against (North Korea) from A to Z, a replica of the Cheonan warship sinking," the North's mission said, referring to the South Korean warship that sank near their tense western sea border in March 2010.

A South Korean-led international investigation found that North Korea torpedoed the warship in 2010, killing 46 South Korean sailors, though Pyongyang has denied its responsibility.

At that time, the North offered to send its team of investigators to the South for a joint probe into the sinking of the warship, a demand rejected by Seoul.

On Sunday, the North's powerful National Defense Commission proposed that the two Koreas conduct a joint probe into the drones, a demand spurned by South Korea. (Yonhap)