WASHINGTON — Congressional negotiations on a year-end spending deal remained at a standstill Wednesday as leaders prepared to move a stop-gap funding bill that would allow talks to continue beyond the Friday deadline and into early next week.

Leaders in the House and Senate said they are making progress on a deal but there are still differences over several policy riders that Republican lawmakers want to attach to the must-pass legislation. The talks have been further complicated by negotiations on a package of tax breaks and Republican calls to lift a ban on oil exports.

Government spending is set to run out at the end of the week, but House leaders on Wednesday announced plans to vote Friday on a stop-gap spending bill, or continuing resolution, that would give Congress until Dec. 16 to pass a fiscal 2016 omnibus appropriations package. Negotiators plan to work through the weekend and a vote on any deal could occur as early as Monday.

“We’re making some progress, but it’s been slow,” said House Appropriations Committee Chairman Harold Rogers, R-Kentucky.

The spending talks have been going on for weeks as Democrats and Republicans continue to battle over Republican lawmakers’ push to add to the bill policy provisions that would, among other things, roll back some clean air and water act regulations, make changes to the 2010 Dodd-Frank Wall Street reform bill and end a 40-year old ban on crude oil exports.