WASHINGTON (Reuters) - President Joe Biden on Wednesday singled out Amazon.com Inc for not paying federal taxes during his address in Pittsburgh, Pennsylvania, as he spoke about raising the burden of taxes on multinational companies and hiking the corporate tax rate. Biden’s infrastructure plan unveiled earlier in the day increases the corporate tax rate to 28% from 21% and changes the tax code to close loopholes that allow companies to move profits overseas, according to a 25-page briefing paper released by the White House. Biden said Amazon was one of 91 Fortune 500 companies that “use various loopholes where they pay not a single solitary penny in federal income tax,” in sharp contrast to middle class families paying over 20% tax rates. “I don’t want to punish them but that’s just wrong,” he said. In response, an Amazon spokeswoman pointed to tweet on research and development tax credits by Jay Carney, the company’s public policy and communications chief and a former White House press secretary under former President Barack Obama. “If the R&D Tax Credit is a ‘loophole,’ it’s certainly one Congress strongly intended. The R&D Tax credit has existed since 1981, was extended 15 times with bi-partisan support and was made permanent in 2015 in a law signed by President Obama,” Carney tweeted. After paying $0 in federal taxes for two years, Amazon started paying federal income tax in 2019. This is not the first time Biden has gone after Amazon. In June 2019, he named Amazon and said no company making billions in profits should pay a lower tax rate than firefighters and teachers.