Fed's Rosengren says too early for QE3: CNBC

US economic growth has been weaker than economists had expected, but it is still too soon for the Federal Reserve to consider additional bond purchases, Boston Fed President Eric Rosengren said on Monday.

Rosengren also did not rule out a third round of quantitative easing of monetary policy, or QE3.

"I think it's too soon to make that determination," Rosengren told CNBC Television. "It's too soon to determine what the next steps for monetary policy are."

The latest bad news on the economy came on Friday, when the Labor Department's employment report for May proved much weaker than expected. Since then, markets have begun speculating about the possibility that the Fed, whose USD 600 billion bond-buying stimulus program ends in June, might have to do more to support the recovery.

That program faced a lot of political opposition when it was first launched, but Rosengren said the Fed would make its decision on policy based on what the economic backdrop merits.

"I don't think politics should play a large role in what we're doing, it should be focused on what the right economic outcomes are and what the right monetary policy is to get those outcomes," he said.

Rosengren, considered one of the more dovish members of the Federal Open Market Committee, did suggest the expansion's softness might delay the day when the Fed eventually begins to withdraw stimulus.

"The slowdown does change when you think the timing would be for when an exit strategy would be appropriate.

Rosengren is not a voter on the FOMC this year.