Iranian President Hassan Rouhani condemned Tuesday airstrikes launched by the U.S. and its allied Arab nations against Islamic State group targets in Syria. Rouhani said the bombings that began Monday were illegal because they occurred without approval from the Syrian government or the United Nations.

U.S. airstrikes in Syria differ from similar military action in Iraq because Syrian President Bashar Assad never requested or authorized foreign intervention within his nation’s borders, Rouhani told NBC’s Andrea Mitchell in an exclusive interview. The Iraqi government had specifically asked President Barack Obama for U.S. aid in its fight against the Islamic State group, also known as ISIS.

Rouhani, who is in New York this week for a U.N. meeting, said he will not meet with Obama during his visit. “I do believe this meeting will probably not take place,” he said.

Rouhani’s comments came just days after the Iranian leader blasted Obama’s planned coalition to “degrade and destroy” ISIS as “ridiculous,” specifically criticizing America’s aversion to the use of ground troops. "Are Americans afraid of giving casualties on the ground in Iraq? Are they afraid of their soldiers being killed in the fight they claim is against terrorism?" he said. "If they want to use planes and if they want to use unmanned planes so that nobody is injured from the Americans, is it really possible to fight terrorism without any hardship, without any sacrifice? Is it possible to reach a big goal without that? In all regional and international issues, the victorious one is the one who is ready to do sacrifice.”

At the same time, he condemned ISIS for its brutal tactics and vowed that Iran would provide Iraq with aid if requested. “They want to kill humanity, and from the viewpoint of Islamic tenets and culture, killing an innocent people equals the killing of the whole humanity,” Rouhani said. ISIS has killed and terrorized thousands of Iraqi Yazidis as well as several Western journalists in recent months.

The U.S. military, along with Bahrain, Qatar, Saudi Arabia, Jordan and the United Arab Emirates, struck at Islamic State group targets in Raqqa, Deir al-Zor, Hasakah and Albu Kamal. At least 20 Islamic State group militants were killed in the Monday-night strikes, according to the Syrian Observatory of Human Rights.