In 1994, he began working at the Ministry of Planning and International Cooperation of Palestine. His diplomatic journey progressed when he was appointed as the Non-Resident Ambassador to Japan and Korea by 1999. During this period, Ambassador SIAM focused on strengthening diplomatic ties with Korea and Japan. He played a pivotal role in establishing the Permanent General Mission of Palestine in Japan, which officially launched in 2003. Over the years, he has held the positions of Resident Ambassador to Japan and Non-Resident Ambassador to Korea. Ambassador Siam has dedicated himself to fostering amicable relationships between Japan, Korea, and Palestine, striving for the recognition of the Palestinian state within their shared commitment to a two-state solution.