JERUSALEM — A top aide to Israeli Prime Minister Benjamin Netanyahu resigned on Thursday, citing personal reasons.

Dore Gold, the director general of Israel’s Foreign Ministry, described the post in a statement as the “high point” of his career and said he would continue to make himself available to help the prime minister.

The American-born Gold has been one of Netanyahu’s closest confidants for some 25 years. He served as Israel’s ambassador to the U.N. during Netanyahu’s first term in office in the 1990s, has often served as a semi-official adviser and joined the Foreign Ministry in 2015.

With Netanyahu holding the foreign affairs portfolio, Gold has often served as a de facto foreign minister, helping forge closer ties with countries in Africa and the Arab world.

Later Thursday, Netanyahu’s office said that Yuval Rotem, former Israeli ambassador to Australia and former consul general in Los Angeles, will take on the role of director general.