North Korea on Monday accused US and South Korean authorities of fabricating the results of a probe that concluded that Pyongyang sent small surveillance drones to spy on key South Korean installations in March. A spokesman for the North's military attacked the United States for what it said was a blindly-backed confrontational conspiracy devised by the government of South Korean President Park Geun-hye, calling him a "political prostitute". "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 unnamed spokesman said in a statement carried by the official news agency. South Korean Ministry of Defence spokesman Kim Min-seok termed the North's statement as "deeply regrettable". "North Korea isn't a real country is it? It doesn't have human rights or freedom. It exists solely to prop up a single person," said Kim at a briefing in Seoul. Earlier in a statement, the North Korea has previously likened the South Korean President to a "comfort woman". In April, North Korea described Barack Obama as Park's "pimp", and in an article this month called the US President a "wicked black monkey". South Korean and US officials jointly examined three drones that were recovered in three different locations near the Korean border over a two-week period starting in late March. In April, North Korea proposed a joint probe into the crashed drones with the South, but Seoul rejected the proposal. North Korea said in the statement the joint investigation into the origin of the drones was a "charade", designed to divert public criticism of the South Korean government's handling of the Sewol ferry tragedy. Park's government has faced continued criticism for not initiating a swifter initial response that could have saved many more lives.