The Obama administration is considering new measures in its final months in office to strengthen the landmark nuclear agreement with Iran, senior U.S. officials said, with President-elect Donald Trump’s first appointments foreshadowing an increasingly rocky road for the controversial deal.

Action under consideration to buttress the pact includes steps to provide licenses for more American businesses to enter the Iranian market and the lifting of additional U.S. sanctions...

The Obama administration is considering new measures in its final months in office to strengthen the landmark nuclear agreement with Iran, senior U.S. officials said, with President-elect Donald Trump’s first appointments foreshadowing an increasingly rocky road for the controversial deal.

Action under consideration to buttress the pact includes steps to provide licenses for more American businesses to enter the Iranian market and the lifting of additional U.S. sanctions.

The effort to shore up the agreement was under way before the election and is not aimed at boxing in Mr. Trump, who opposes the deal, the officials said. Officials also acknowledged the proposals are unlikely to make the nuclear agreement more difficult to undo.

Mr. Trump’s first two picks for his national security team—retired Army Gen. Mike Flynn as national security adviser and Rep. Mike Pompeo (R., Kan.) as Central Intelligence Agency director—are hard-liners on Iran who have voiced opposition to the nuclear deal.

Trump transition team officials didn’t respond to questions about their plans for the agreement or the current administration’s efforts to shore it up.