Prime Minister Narendra Modi today greeted his Pakistan counterpart Nawaz Sharif on his birthday, notwithstanding the severe chill in relations between the two countries."Birthday wishes to Pakistan PM Mr. Nawaz Sharif. I pray for his long and healthy life," PM Modi tweeted.Mr Sharif turned 67 today.Mr Modi extended birthday wishes to Sharif even though the two countries have been witnessing a severe chill in their relations because of repeated terror attacks in India emanating from Pakistan.Last year on this day, PM Modi had made a huge gesture by travelling to Lahore on an unscheduled visit to wish Mr Sharif personally and attend the marriage ceremony of his relative.However, the warmth in the bilateral ties witnessed at that time evaporated after terror attack on the airbase in Pathankot on January 1 this year. Since then the relations have just been sliding as tensions escalated.Source: NDTV