[5] He joined Israel's Ministry of Foreign Affairs in 1990, serving as deputy chief of mission at the Consulate General in Hong Kong, and spokesman at the Israeli Embassy in Beijing.

[7][better source needed] He served as ambassador for four years before returning to Israel in August 2020 to become prime minister Benjamin Netanyahu's Senior Advisor for Foreign Affairs and International Communications, replacing Evan Cohen.

[16] In one interview on MSNBC, host Medhi Hasan accused Regev and other Israeli government figures of spreading disinformation about civilian casualties in Gaza.

"[18] In the same interview, he described South Africa's genocide case against Israel at the International Court of Justice as "very sad, because they basically decided to become Hamas' lawyer.

[19][6][better source needed] Amid allegations that Israel was committing genocide in Gaza, Aboriginal activist Robbie Thorpe brought a private prosecution against Regev in 2024.

[20] The charge was based on remarks Regev made during a radio interview on 10 October 2023 in which he advocated for Israel to cut off the supply of essentials such as food, water and electricity to Gaza.