(Reuters) - Iran's military chief met with Syrian President Bashar al-Assad on Thursday during a visit to Damascus to set out a joint military strategy, Syria's state news agency reported, a sign of deepening Iranian influence that has alarmed Israel.

General Mohammad Baqeri said Iran was determined to continue supporting the Syrian leadership and people "until security and safety are returned to them" and would help with reconstruction, the state news agency SANA said.

Israel has voiced deep concern over Tehran's widening influence in Syria, where Iranian forces and Iran-backed militias including Lebanon's Hezbollah have played a critical role helping Assad in the six-year-long war.

On Tuesday, Baqeri, speaking from Damascus, warned Israel against breaching Syrian airspace and territory and pledged to increase cooperation with Syria's military to fight both Israel and Sunni jihadist militants.

Israel's air force says it has struck arms convoys of the Syrian military and Hezbollah nearly 100 times during the war.

Israeli Prime Minister Benjamin Netanyahu has said that Iran was strengthening its foothold in Syria and that Israel would "do whatever it takes" to protect its security.

Tensions have risen this year between Lebanon's Hezbollah and Israel, which have avoided a major conflict since 2006.

In the meeting with Baqeri, Assad said the Iranian people and armed forces were a key partner in victories "against terrorism in Syria", SANA reported.

Military support from Iran and Russia has helped Assad regain swathes of Syria from rebels and Islamic State militants.