The administration of U.S. President Donald Trump is considering refusing visas and increasing restrictions on several delegations attending a high-level United Nations meeting this month.

The Trump administration has refused to issue visas to Palestinian President Mahmoud Abbas and his large delegation to attend the high-level UN meeting this month.

The restrictions would severely limit the delegations’ ability to travel outside New York City.

According to an internal State Department memo obtained by The Associated Press, potential travel restrictions and other limitations could soon be imposed on delegations from Iran, Sudan, Zimbabwe, and possibly, unexpectedly, Brazil during the high-level leaders’ gathering at the UN General Assembly starting September 22.

While the potential restrictions are still under review and circumstances may change, the proposals represent another step in the Trump administration’s visa crackdown, including a broad review of those who already hold legal entry permits to the U.S. and those seeking to enter the country to attend the UN meeting.

Strict restrictions are already imposed on the movements of Iranian diplomats in New York, but one proposed measure would prevent them from shopping at major wholesale stores reserved for members only, such as Costco and Sam’s Club, without explicit permission from the State Department.

These stores have long been favored by Iranian diplomats assigned or visiting New York because they can purchase large quantities of products not available in Iran at relatively low prices and send them back home.

It is not yet clear if or when the proposed shopping ban for Iran will take effect, but the memo said the State Department is also considering drafting rules that would allow it to impose terms and conditions on wholesale club memberships for all foreign diplomats in the U.S.

Regarding Brazil, it is unclear whether any potential visa restrictions would affect Luiz Inácio Lula da Silva or lower-ranking members of the country’s delegation to the high-level UN gathering.

The Brazilian president traditionally is the first world leader to speak before assembled leaders on the opening day of the session, with the U.S. president typically speaking second.

Lula has been a target of the U.S. president, who objects to the trial of his friend, former President Jair Bolsonaro, on charges of leading a coup attempt.

One country expected to face fewer restrictions is Syria, whose delegation members have received exemptions from travel restrictions to the UN for more than a decade.

Although Sudan and Zimbabwe were mentioned as potential targets, the memo did not specify what restrictions might be imposed on their delegations.

The State Department did not immediately comment.