Against the backdrop of tense talks over trade, US President Donald Trump today called Prime Minister Narendra Modi a "tough negotiator" as he talked about a "fantastic trade deal" between the two countries. "We are working on a very comprehensive trade deal between India and the United States... one that will benefit both nations.... India is a very large market for US exports and US is India's largest market in terms of export...so a strong US is great for India," President Trump said.