Iran's Ministry of Foreign Affairs (MFA) has called the US an accomplice in the assassination of the head of the political bureau of the Palestinian Hamas movement, Ismail Haniyeh, in Tehran.

"The Ministry of Foreign Affairs emphasizes the accountability of the US government as an accomplice in the implementation of this heinous act of terrorism and the continuation of the occupation and genocide of Palestinians by the Zionist (Israel) regime.

"This terrorism is not only a gross violation of the principles and norms of international law as well as the UN Charter, but also a serious threat to international peace and regional security," the Iranian MFA said in a statement.