'Volatility in financial markets and a moderating outlook in labor markets could pose downside risks to growth,' said a CB director.
Initial claims for unemployment benefits fell last week to the lowest level since April, 259,000.
The Fund reduces its forecast from 2.4% in April and says there is a "clear case" for the Fed to proceed cautiously on interest rates.
A Harvard University study finds the number of Americans dedicating at least half of their income toward rent hit a record 11 million in 2014.
"The balance of evidence points to notable downward economic risks to the U.K. economy" if the country leaves the EU, the Fund warns.
Despite the decline in May, the pace of home building remains well ahead of last year amid steady demand from buyers.
Core consumer prices increased 0.4% in May, pushed up by high rents for primary residences, said the Labor Department.
The Bank of England expects the exchange rate of sterling to fall further, 'perhaps sharply,' if Britain votes to leave the EU.
The 0.5% increase last month follows April's 1.3% surge, supporting the view that U.S. growth is rebounding.
With recent economic indicators mixed, a "cautious approach to adjusting monetary policy remains appropriate," the Fed says.