WASHINGTON -- Fresh off an overwhelming victory in the midterm elections and sitting on an even larger majority in the House of Representatives, Speaker John Boehner (R-Ohio) was anything but conciliatory Thursday, chastising President Barack Obama for "playing with matches" and pledging to challenge the administration on multiple fronts.

Speaking to reporters in his first news conference since the GOP won control of the Senate and added at least a dozen seats in the House, Boehner vowed to hold more votes to repeal Obamacare and challenge existing regulations. He also promised a tough response if Obama tries to do anything on his own.

"Finding common ground is hard, but it's even harder if the president isn't willing to work with us," Boehner said, before explaining that his members will move to repeal the Affordable Care Act, even if such a bill won't pass the Senate or be signed by the president.

He warned that if Obama tries to take executive action on things like immigration reform -- as the president signaled he would Wednesday if Congress continues to stall -- it would "poison the well" and prompt a harsh response from Republicans.

"When you play with matches, you take the risk of burning yourself," Boehner said. "And he's going to burn himself if he continues to go down this path."

Obama said before the election that he had a pen and he would use it when Congress is gridlocked, prompting Republicans to step up their criticism of Obama as an arrogant, imperial leader.

"The American people made it clear Election Day, they want to get things done, and they don't want the president acting on a unilateral basis," Boehner said.

Boehner's stark rhetoric made clear there would not be much in the way of a honeymoon for the new Congress, forecasting potentially bruising showdowns with the White House over the next two years.

In terms of priorities, Boehner went through a GOP wish list that closely resembled what soon-to-be Senate Majority Leader Mitch McConnell (R-Ky.) highlighted on Wednesday. The agenda included approving the Keystone XL Pipeline, repealing Obamacare's definition of full-time work as 30 hours a week, reforming the tax code and passing legislation related to school choice.

Boehner conceded that the Senate may not have the votes to repeal Obamacare, but said his chamber would proceed with the matter anyway. He added that "bipartisan majorities" interested in eliminating at least some parts of the law exist in both the House and Senate.

"Just because we may not get everything we want, doesn't mean we shouldn't try to get what we can," Boehner said.