Nafiz Albayrak / New York, Sep 18 () - The U.S. Federal Reserve kept interest rates unchanged, in a nod to concerns about a weak world economy, but left open the possibility of a modest policy tightening later this year.

"Recent global economic and financial developments may restrain economic activity somewhat and are likely to put further downward pressure on inflation in the near term" the Fed said in its policy statement following the end of a two-day meeting. It added the risks to the U.S. economy remained nearly balanced but that it was "monitoring developments abroad."

The central bank maintained its bias toward a rate hike sometime this year, while lowering its In deciding when to hike rates, the Fed repeated that it wanted to see "some further improvement in the labor market" and be "reasonably confident" that inflation will increase.