External Affairs Minister Subrahmanyam Jaishankar on Monday formally joined the BJP in the presence of party working President JP Nadda at the Parliament House. Jaishankar had served as Foreign Secretary from January 2015 to January 2018 and succeeded Sushma Swaraj as External Affairs Minister last month. Jaishankar also served as the Indian ambassador to the US from 2013 to 2015.