NEW DELHI, Dec 28: Prime Minister Narendra Modi and his Pakistani counterpart Nawaz Sharif may meet in Washington towards end of March on the sidelines of the Nuclear Security Summit. US President Barack Obama has invited both the leaders to take part in the international meet on nuclear security, and it if both the leaders were there at the same time, a meeting between them could not be ruled out, it is understood. However, no official announcement has been made about the visit to Washington. Mr Modi and Mr Sharif in recent months had had three meetings. First, they held talks in Ufa in Russia on the sidelines of the SCO Summit, and then they had a surprise brief meeting in Paris during the climate change Summit. The Paris encounter was followed by the surprise of the year when Mr Modi made a sudden decision to make a stopover at Lahore on the Christmas day while on way to New Delhi from Kabul after Mr Sharif suggested the idea to him when he called him to wish him on his birthday. If the two Prime Ministers meet in Washington for the Conference, which will be held on March 31-to April 1, it would give them an opportunity to review the progress on the implementation of the decision by the two countries to start comprehensive dialogues. Their Foreign Secretaries would be meeting in Islamabad on January 15. (UNI)