Rep. Paul Ryan (R-Wis.), the new chairman of the influential House Ways and Means Committee, said Friday that lawmakers probably need to make meaningful strides on tax reform by the end of the summer in order to stand a chance of achieving a consequential changes to the tax code in the near future.

"If it goes past summer, it's hard to see," Ryan told reporters. He later added: "I just think, knowing the way the budget process works on tax reform, if we haven't done it in 2015, which is effectively through summer, then it probably won't happen."

Ryan declined to set a hard deadline, but predicted that tax reform can be done in "somewhere between one and three years." Business tax reform, he said, could be the bulk of "phase one" of the process, and "phase two" could be to "finish the job of comprehensive tax reform."

Republicans and Democrats have identified areas of possible agreement in rewriting the tax code, including lowering the top rates for large corporations.

In an hour-long question-and-answer session, Ryan, the 2012 GOP vice presidential nominee, said he decided not to run for president, "because I think the best place for me is right here," at the helm of the committee that writes the nation's tax laws. He identified two goals for the next two years: Putting "big ideas" out there to contrast with President Obama's, but also finding areas of "common ground" with the president.

"These are not mutually exclusive goals," said Ryan.

Tax reform and trade are two areas where Ryan expressed optimism about reaching a deal with the president. Most Republicans agree with Obama about a “Trade Promotion Authority" measure that would ease completion of a trade deal with Asia-Pacific nations. The biggest obstacle to passing such a measure will probably be Democrats who oppose it.

"I think this is the most promising issue. I think this one has the biggest opportunity for an enormous effect to help the country," said Ryan of trade.

While the session was much heavier on policy than on politics, Ryan did talk a little about his political future. Asked whether he might agree to be anyone's vice-presidential running mate again, Ryan responded: "That doesn't happen twice."