Pharma stocks declined after US President Donald Trump reiterated tariffs on pharmaceutical imports.The new tariffs are likely to prompt pharmaceutical companies to reconsider their operations in China and relocate to the US.Nifty Pharma declined as much as 2.64% on Wednesday compared to 0.56% decline in the benchmark Nifty 50.The stock market has experienced extreme volatility over the last couple of trading sessions due to ongoing trade tensions.