Prime Minister Narendra Modi met his Pakistani counterpart Nawaz Sharif here on Thursday ahead of Friday's Shanghai Cooperation Organisatipn (SCO) Summit.According to a source here, Modi enquired about Sharif's health after an open heart surgery in London in May last year."Both leaders greeted each other at the Leaders' Lounge at the Astana Opera on Thursday evening before the SCO concert," the source said.India and Pakistan are expected to be granted full membership of the SCO at the summit in the Kazakhstan capital, making them the seventh and eighth members of the Eurasian bloc that includes China, Kazakhstan, Kyrgyzstan, Russia, Tajikistan, and Uzbekistan.This is the first time that the Indian and Pakistani Prime Ministers have met since Modi made a surprise visit to Lahore on December 25, 2015, on his way back to India from Kabul because of Sharif's birthday.This happened after India and Pakistan decided to start a comprehensive bilateral dialogue during External Affairs Minister Sushma Swaraj's visit to Islamabad earlier that month.However, ties between the two countries collapsed after a cross-border terror attack on an Indian Air Force base in Pathankot on January 2, 2016.India has blamed the Pakistan-based terror outfit Jaish-e-Mohammad for the attack.According to the source here, Modi, while exchanging pleasantries with Sharif, also enquired about the latter's mother and family.Sharif was among the South Asian leaders who attended the swearing-in ceremony of the NDA government led by Modi in May 2014.