Investing.com - President Trump says he will propose additional tax cuts later this year, but one Wall Street firm says the previous round has already damaged the nation's fiscal condition. In a note to clients, Goldman Sachs (NYSE:GS) says the fiscal outlook "is not good," with deficits expected to soar in the coming years.The firm says the nation's growing debt burden will slow economic growth, raise interest rates and likely hamper the government's ability to provide fiscal stimulus during the next economic downtown.Goldman forecasts the deficit will jump from $825 billion, the equivalent of 4.1% of the nation's economic output, to $1.25 trillion in 2021, or 5.5% of gross domestic product. By 2028, the deficit will hit $2.05 trillion, or 7.0% of GDP. The President's $1.5 trillion tax cut package of 2017 permanently slashed corporate rates but reduced personal ones on only a short-term basis.