Turkey has decorated Saudi Arabia's King Salman with the country's highest state medal in recognition of the close ties between the two countries.

Turkish President Recep Tayyip Erdogan on Tuesday bestowed the medal, saying the Saudi monarch had exerted "great efforts" to forge friendly ties since taking the throne.

Saudi Arabia and Turkey are both strong supporters of the opposition forces in Syria and have been building strong military ties. Turkey participated in military drills in Saudi Arabia this year. Riyadh has deployed warplanes at a Turkish air base as part of the anti-Islamic State coalition.

Talks during the king's three-day visit were expected to focus on Syria and other regional issues.

King Salman is scheduled to attend an Islamic Cooperation summit in Istanbul later in the week.