Congressional leaders have tentatively agreed on a two-year bill to overhaul federal highway programs that drops a requirement that the government approve the Keystone XL oil pipeline.

Senate aides said they were working Wednesday to put the agreement into legislative language, which must happen before House and Senate leaders formally sign off on the deal. They spoke on condition of anonymity because the deal wasn't final.

House Republicans had pushed for inclusion of the Keystone provision, but the White House threatened to veto the bill if it was included.

Aides said another GOP provision blocking the federal government from regulating the toxic ash generated by coal-fired power plants was also dropped.

Lawmakers plan to give final approval to the bill this week. Highway programs are due to expire on Saturday.