Singh said Khan should not forget that he was disrobed during frisking at JFK airport in New York on his previous visit.
"Khan was frisked threadbare at JFK airport. Is he ready to go to US again, where the UN office is situated and get disrobed again?" Singh told reporters after paying obeisance at Vindhyachal temple here.
"Last time, he got me and Jaya Prada expelled from the party. God knows what will happen this time. I may be expelled from world," he claimed.
Commenting on Prime Minister Narendra Modi, he said, "When Indo-US nuclear pact was signed during the UPA government, we were criticised. Now Modi is doing the same thing and he is being praised."
Earlier, the former SP leader inaugurated a day-long community kitchen organised here. He was accompanied by former SP MP Jaya Prada and film producer Boney Kapoor.