BALTIMORE — Republicans said today that they will attempt to force the Keystone XL pipeline into a deal on extending the payroll tax cut, further complicating an already difficult negotiation.

House Energy and Commerce Chairman Fred Upton, a member of the payroll tax conference committee, said he will push hard for the pipeline to be built, despite President Barack Obama’s decision this week to deny the project the proper permits.

“As much as the president would like this issue to go away and maybe come back after the election, we’re going to do everything we can to keep it on the front burner,” the Michigan Republican said.

One option, he said, might be to take the decision out of Obama’s hands.

Republicans scored a political win in December’s short-term payroll tax cut deal by including a provision forcing the president to make a decision on the pipeline within 60 days.

Obama announced Wednesday that the State Department did not have enough time to adequately review the project in the time allotted but left open the door for TransCanada Corp., the firm shepherding the pipeline, to apply again. Republicans say that is not enough.

“The president’s excuse this time was we didn’t give him enough time,” said Rep. Greg Walden (Ore.), another Republican conferee. “If we gave him 60 days and that wasn’t enough time, why did he only take 26 to say no to American jobs?”

The conference committee will meet for the first time next week. Walden said the Republican conferees met once earlier this week but have not yet huddled to discuss their options at the House GOP retreat that they are holding here.

Although a number of the sessions at the retreat are on broader political issues — particularly the 2012 elections and polling on Obama — lawmakers said the main focus of this year’s conference remains the effort by leadership to bring Republicans together.

“The focus here has really been about the House Conference and how we’re going to proceed” this year on issues such as the debt, deficit and spending, Rep. Lee Terry (Neb.) said.

But more fundamentally, Speaker John Boehner (Ohio) is making a push to bring his Conference back into line and rebuild the GOP’s unity following December’s collapse over the payroll tax cut bill.

According to Terry, much of the discussion has focused on “here’s how the Conference needs to work.”

Like a number of his colleagues, Terry conceded that, “we need to get on the same page here. We can’t let what happened in December happen again.”

But Terry also acknowledged that it is unclear whether that lesson will be learned.

“Everyone agrees we need to work better with each other. [But] yeah, you never really know until it’s tested,” he said.