The Foreign Minister of the Islamic Republic of Iran, Seyed Abbas Araghchi, arrived in the Lebanese capital, Beirut, on Tuesday morning as part of his regional tour following his visit to Egypt.   During his one-day visit to Lebanon, Araghchi is scheduled to meet with his Lebanese counterpart as well as the president, parliament speaker, and prime minister of Lebanon.   Key topics of discussion with high-ranking Lebanese officials will include bilateral ties between Iran and Lebanon, regional developments, particularly the situation in Palestine, and the continued aggression of the Zionist regime against Lebanon and Syria.