CINCINNATI (AP) -- Ohio Sen. Rob Portman is tamping down running mate speculation that flared up this week after he was in Boston with Mitt Romney campaign officials.

Portman says he was there Monday to help with fundraising and to discuss strategy in the Republican presidential candidate's campaign. He says a weekend trip to New Hampshire just before Boston was in response to that state's Republican Party's request that he speak at a fundraiser and also to make some college visits in the region with his daughter.

Portman told Ohio reporters in a conference call Thursday that the trip had been planned "for a while" and wasn't about the vice presidential search.

The former congressman and Bush administration official is widely believed to be among the top contenders for the GOP ticket.