Iran and Syria condemned on Thursday Saudi Arabia's airstrikes against Houthi rebels in Yemen.
Iranian Foreign Minister Javad Zarif urged for an "immediate stop" to the operations in Yemen, calling them a violation of the country's sovereignty.
"We will spare no effort to contain the crisis in Yemen," Zarif told Iran's official news network Al-Alam.
Separately, the Syrian Arab News Agency described the Saudi-led airstrikes on Houthis as a "blatant aggression."
Saudi Arabia and its Arab allies launched a military operation, including airstrikes, against Houthi positions in Yemen late Wednesday.
In a joint statement issued earlier Thursday, Saudi Arabia, the United Arab Emirates, Bahrain, Qatar and Kuwait said the operation had come "in response to a request by Yemeni President Abd Rabbuh Mansour Hadi to protect Yemen from the aggression of Houthi militias."
Arab states including Sudan and Libya's Tobruk government, have expressed support for the Saudi-led offensive, which is also backed by the United States.
Pakistan is also considering a request from Saudi Arabia to support the military operation against the Shia Houthi militia.
Meanwhile, Iraq's Foreign Minister said on Thursday that his government rejects the offensive.
Yemen has been rocked by turmoil since September 2014 when pro-Houthi forces overran Sanaa, from where they have since sought to extend their influence to other parts of the country.
Some Gulf States accuse predominantly-Shia Iran of supporting the Houthi insurgency.