He also spoke to Singh and extended birthday greetings to him.
"Warm birthday wishes to Dr. Manmohan Singh ji. May God bless him with a long and healthy life," he said in a tweet."
PM @narendramodi spoke to Dr. Manmohan Singh ji and extended birthday greetings to him," the PMO said in a tweet.
Singh, who served as Prime Minister from 2004 to 2014, was born in Gah in Pakistan. Singh's family migrated to India during partition in 1947.