WASHINGTON (Reuters) - Republican lawmakers will try to force the Obama administration to approve the Canada-to-Texas Keystone XL pipeline by attaching it to a highway bill that Congress will consider next month, House of Representatives Speaker John Boehner said on Sunday.

President Barack Obama earlier this month denied TransCanada's application for the oil sands pipeline, citing lack of time to review an alternative route within a 60-day window for action set by Congress.

Republicans have since been looking for a vehicle to resurrect the $7 billion project, and Boehner said that would be a House Republican energy and highway bill.

"If (Keystone) is not enacted before we take up the American Energy and Infrastructure Jobs Act, it will be part of it," Boehner said on ABC's "This Week" news program.

Environmentalists and some Democrats oppose Keystone, citing higher greenhouse gas emissions, while most Republicans say it would create needed jobs.

Republicans in the Senate also plan to introduce a Keystone bill. Some Senate Democrats back the pipeline, but its passage is not guaranteed in the body.

Parts of the House Republican plan, such as opening up the Alaska National Wildlife Refuge to oil exploration, stand little chance of passing the Democratic-controlled U.S. Senate.

Attaching Keystone to a pending deal to extend payroll tax cuts for workers, which has greater bipartisan backing than the highway bills, is another vehicle Republicans are considering.

(Reporting By Kim Dixon; Editing by Paul Simao)

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