Iran said it appointed an ambassador to Egypt for the first time since the two sides froze diplomatic relations more than three decades ago, the website of the Iranian government’s official English-language channel, Press TV, reported late Monday.

Also Monday, officials at Egypt’s Ministry of Foreign Affairs confirmed that new foreign minister Nabil Elaraby is considering a visit to the Gaza Strip—an area controlled by Hamas, a militant Palestinian Islamist group backed by Tehran and until now shunned by Cairo.

The announcements follow a rare meeting earlier this month between a high-level Iranian diplomat and Mr. Elaraby, after which the foreign minister told reporters that Egypt has “opened a new page” with Iran.

American officials said they are concerned that Egypt’s apparent determination to re-establish relations with Iran is part of a broader reordering of its foreign policy. They worry that such a turn could empower Iran and its regional clients Hamas in the Gaza Strip and Hezbollah in Lebanon, both of which are labeled terrorist groups by the U.S.