WASHINGTON : President Trump’s advisers are debating an order intended to designate the Muslim Brotherhood as a foreign terrorist organization, targeting the oldest and perhaps most influential Islamist group in the Middle East, The New York Times reported Wednesday.

A political and social organization with millions of followers, the Brotherhood officially renounced violence decades ago and won elections in Egypt after the fall of President Hosni Mubarak in 2011. Affiliated groups have joined the political systems in places like Tunisia and Turkey, and President Barack Obama long resisted pressure to declare it a terrorist organization.

Officially designating the Brotherhood as a terrorist organization would roil American relations in the Middle East. The leaders of some American allies — like Egypt, where the military forced the Brotherhood from power in 2013, and the United Arab Emirates — have pressed Mr. Trump to do so to quash internal enemies, but the group remains a pillar of society in parts of the region.

The proposal to declare it a terrorist organization has been paired with a plan to similarly designate Iran’s Islamic Revolutionary Guards Corps, according to current and former officials briefed on the deliberations. Leaders of the corps and its Quds Force unit have already been put on a government terrorist list, but Republicans have advocated adding the corps itself to send a message to Iran.

The Iran part of the plan has strong support within the White House, but momentum behind the Muslim Brotherhood proposal seems to have slowed in recent days amid objections from career officials at the State Department and the National Security Council, who argue that there is no legal basis for it and that it could alienate allies in the region. Former officials said that they had been told the order would be signed on Monday, but that it had now been put off at least until next week.

The delay may reflect a broader desire by the White House to take more time with executive actions after the chaos associated with hastily issued orders, like the temporary ban on visitors from seven predominantly Muslim countries. But it also underscored the complex dynamics involving the Muslim Brotherhood, whose chapters have only loose relationships across national lines.