The president of Syria, Iran’s closest ally in the Middle East, has arrived in Tehran for a two-day visit. Bashar al-Assad, who was greeted by his Iranian counterpart Mahmoud Ahmadinejad, will be holding talks with top officials including Supreme Leader Ayatollah Ali Khamenei. Discussions will center on the crisis in Lebanon and instability in Iraq. Washington accuses Tehran and Damascus of fomenting tensions in Iraq by allowing fighters to enter the country and providing financial help. They deny the allegations.