First quarter gross domestic product stats from the US Commerce Department showed an increase of two percent, revised down from the 2.2 percent it reported last month.
The lower than expected growth comes amid the weakest consumer spending in nearly five years.
Despite the downgraded figures for Q1, President Trump’s $1.5trillion tax cut package, which was passed in January, is expected to drive economic growth in the second quarter.
The stimulus created by the tax break is predicted to boost growth and surpass the administration’s target of three percent – with some estimates putting the figure as high as 5.3 percent.
But economists have warned Mr Trump’s trade tariffs, the first of which targeted imported solar panels and washing machines in January, could damage America’s long-term economic prospects.
The Trump administration has since signed off tough new levies on steel and aluminium imported from major trade partners including the European Union, Canada and Mexico.
The move has prompted retaliatory tariffs on US products including jeans and motorcycles.
Washington is also involved in a tit-for-tat trade war with China after imposing billions in tariffs on goods from the Asian superpower.
Gus Faucher, chief economist at PNC Financial Services in Pittsburgh, said: “Trade is a significant downside risk.
“The potential of a trade war that threatens the global economic expansion could lead to weaker US economic growth.”
However analysts say the moderate Q1 growth should not necessarily be viewed as a true reflection of the economy’s health because GDP is typically weaker at the beginning of the year.
And the Commerce Department stats showed gross domestic income (GDI), a different method of measuring growth, increased at 3.6 percent between January and March.
This was revised up in today’s stats from a previous estimate of 2.8 reported last month.
The average of GDP and GDI, known as gross domestic output, is considered to be a more accurate way of gauging economic activity, increased by 2.8 percent rate in the first quarter, instead of the 2.5 percent pace estimated in May.