President Hassan Rouhani, addressing flag-waving crowds on central Tehran's Azadi (Freedom) Square, made no specific reference to Israel's air strikes in Syria on Saturday which it said were aimed at air defense and Iranian targets.
But he told the crowd: "They (U.S. and Israel) wanted to create tension in the region ... they wanted to divide Iraq, Syria ... They wanted to create long-term chaos in Lebanon but ... but with our help their policies failed."
Iran backs Syrian President Bashar al-Assad in the civil war, supports Shi'ite militias in Iraq, Houthi rebels in Yemen and Lebanon's Hezbollah.
U.S. President Donald Trump, who sees Iran as a rising threat to regional stability in the Middle East, has pledged to work with Israel and Iran's key regional rival Saudi Arabia to curb what they say are Tehran’s attempts to extend its influence in the region.
Israel has warned about the increased Iranian involvement along its borders with Syria and Lebanon.
Israel's air strikes on Saturday which it said successfully hit air defense and Iranian targets represented the most serious confrontation between Israel and Iranian-backed forces in Syria in the seven-year civil war.
The Syrian army claimed to have brought down an Israeli F-16 after Israel reportedly shot down an Iranian drone which it said had entered Israeli airspace. Iran has denied the Israeli claim, saying its presence in Syria is only advisory.
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