TNN, New Delhi :Prime Minister Narendra Modi on Thursday fired India’s highest-ranking diplomat and replaced her with India’s ambassador to the United States, a day after a successful visit by US President Barack Obama.Modi’s appointment of Subrahmanyam Jaishankar as foreign secretary, the top bureaucrat at the foreign ministry, underscores the Prime Minister’s control over foreign affairs.But his abrupt sacking of Sujatha Singh, the foreign secretary appointed by the previous Congress administration, was criticized by the Congress party.Congress questioned the timing of government’s decision to remove Sujatha Singh and wondered whether it was “retribution” for her stand on IFS officer Devyani Khobragade.”Is sacking of foreign secretary late retribution for her stand on Devyani Khobragade affair? Removal after a presidential visit “coincidental”? former information and broadcasting minister Manish Tewari wrote on Twitter.Government late on Wednesday night decided to replace Sujatha Singh, curtailing her tenure by eight months.Singh was the foreign secretary when the arrest of Khobragade in the US had led to a diplomatic dust-up.The 1999 batch IFS officer was arrested in 2013 in New York on visa fraud charges. The incident had triggered a row between the two countries with India reacting with steps including downgrading privileges of certain categories of US diplomats. Singh as foreign secretary had taken a tough stand on the matter.