A resurging pandemic and potentially protracted negotiations over a new round of economic stimulus could dominate the early months of President-elect Joseph R. Biden’s tenure, overshading other priorities and likely delaying any new major legislation impacting oil and gas interests.

The likelihood of a divided government, moreover, will make Biden’s energy and climate priorities among his heaviest lifts, analysts said. Republicans are poised to retain control of the Senate with GOP candidates favored in two pending run-off elections in Georgia that would determine the upper chamber’s majority. Biden’s political opposition has made clear it would oppose big shifts in policy that would diminish demand for U.S. natural gas and crude oil.

“The fact that Republicans appear...