Investing.com - Ratings agency Moody’s upgraded its growth forecasts for the euro zone's three largest economies on Wednesday and slashed its forecast for the U.S.The agency said it is now expecting “above-potential growth this year and next” in the euro zone.In contrast, Moody's said the U.S. economy has been “weaker” than expected since the start of the year, leading it to cut its forecasts for 2017 and 2018.The ratings agency is also less confident about U.S. President Donald Trump’s commitment to ramp up infrastructure spending.Trump campaigned on a platform promising $1 trillion in infrastructure spending.But a failure to overhaul healthcare has raised doubts over the administration's ability to deliver on its economic agenda.The report came as data on Wednesday showed that the U.S. economy grew by an annualized 3% in the second quarter, up from an initial estimate of 2.6%.