New Delhi, Sept. 21 -- There is "guarded optimism" that the US will eventually bring down the 50% tariff on exports from India, a senior official in New Delhi has said, citing the visit by an American trade negotiating team led by Brendan Lynch that concluded on Wednesday night and sustained diplomatic signals from President Donald Trump, including his birthday call to Prime Minister Narendra Modi. "It's not just the birthday call that made PM refer to taking the relationship to 'new heights' in a post on X. It's also other signs like the reiteration the very next day in UK," the official said. P4...