London, May 9 : Former US President Ronald Reagan believed that aliens were spying on Earth for decades and wanted to invade America, claims a new book.

Reagan, who was President from 1981 to 1989, confided his fear to a pal, telling him that he had seen flying saucers three times, said author Darwin Porter.

He allegedly added: "I just know it. They've selected some desert in the West to make their landing."

However, the ex-President's daughter Patti Davis dismissed the claims, saying her father may have been joking, reports The Sun.

Ex-Soviet Union President Mikhail Gorbachev has claimed the US and USSR made a pact to help each other against an alien invasion.

He added: "President Reagan said to me, `If the US were attacked by someone from outer space, would you help?'" (ANI)