Iranian diplomats and officials visiting the United States will no longer be permitted to shop at Costco or other wholesale retailers without approval from the State Department, according to new restrictions announced by the Trump administration. The regulations were published in the Federal Register as diplomats from around the world were in New York this week for the annual United Nations General Assembly. They apply to Iranian officials and any accompanying family members, and also bar them from “acquiring luxury goods” without State Department permission. The rules tighten longstanding constraints on the activities of visiting officials from Iran, in what experts said was a U.S. effort to further inflame tensions between the Iranian public and political elites — and even to embarrass them over their shopping habits. “These measures are aimed at exploiting sensitivities in Iranian public opinion,” said Omid Memarian, an expert on Iran at DAWN, a Washington-based research group that focuses on the Middle East.