Syria appeared Tuesday to be trying to position itself on the side of the international coalition as the opening salvo hit in what U.S. President Barack Obama has warned will be a lengthy military campaign near the Syria-Iraq border. In contrast, Syria's allies Iran and Russia condemned the strikes.

Damascus appeared to want to show it was not being left out. The government vowed in a statement to continue fighting the extremist factions across Syria, and said it will not stop coordination "with countries that were harmed by the group, first and foremost Iraq."

"The Syrian Arab Republic says it stands with any international effort to fight terrorism, no matter what a group is called — whether Daesh or Nusra Front or something else," it said, using an Arabic acronym for the Islamic State group. "We will not hesitate to take further actions to target and kill terrorists who are trying to attack our country," said Mohammad al-Momani, a government spokesman.

Rohani: Air strikes illegal

Syria's two key allies, Iran and Russia, condemned the strikes.

Iran's President Hassan Rohani said Tuesday the U.S.-led coalition's airstrikes in Syria are illegal because they were not approved by or coordinated with Syria's government.

Russia, meanwhile, warned that the "unilateral" U.S. airstrikes are destabilizing the region and urged Washington to secure either Damascus' consent or UN Security Council support.

Rohani stressed that Iran condemns the Islamic State group — although he did not single them out by that name and referred to only as "terrorists" — for trampling on human rights and torturing and killing civilians. Meeting with editors on the first day of the United Nations General Assembly, he said Iran stands ready to help fight terrorism.

But Rohani said the U.S. policy is confused because it simultaneously opposes the militants while also trying to undermine the government of Syria's President Bashar Assad.

The arming of one group of rebels to fight against the Islamic State group while at the same time encouraging the same rebels to bring down the Assad government is a policy that is "clearly nebulous and ambiguous at best," he said, adding, "I can assure you this will not succeed in the end."

"This is a very confusing behavior and policy."

He suggested Washington now faces a challenge with its "time management" and should consider the goal of fighting the terrorists first and address its issues with the Syrian government later.

Syria's Foreign Ministry said Washington told Damascus' envoy to the United Nations of the impending raids shortly before they began. It also said U.S. Secretary of State John Kerry passed a message through Iraq's foreign minister to Syria's top diplomat to inform Damascus of the plans.

There was no immediate comment from Washington on the Syrian Foreign Ministry's statement.

In the past weeks, Syrian officials insisted that any international strikes against the extremists on its soil must be coordinated with Damascus or else they would be considered an act of aggression against Syria and a breach of its sovereignty. The United States has ruled out any coordination with Assad's government.

The U.S. and five Arab countries began their airstrikes on Islamic State group's targets in Syria around 3:00 A.M. Tuesday Syrian time. U.S. officials said the strikes were conducted by the United States, Bahrain, Qatar, Saudi Arabia, Jordan and the United Arab Emirates.

In Lebanon, Hassan Nasrallah, in a televised speech, also voiced Hezbollah's opposition to the U.S.-led military intervention. "We are against American military intervention and an international coalition in Syria, whether that (action) is against the regime or IS," Nasrallah said in a speech aired on Hezbollah-run al-Manar television. "America, is in our view, the mother of terrorism and the origin of terrorism," he said, adding this meant the United States was not ethically qualified to lead a "war on terrorism".

Meanwhile, Turkish President Erdogan said his country could give military support to U.S.-led coalition.

Red Cross insists on adherence to Geneva Conventions

Meanwhile, a senior official of the International Committee of the Red Cross said the United States and its allies must comply with the rules of war in carrying out air strikes on Islamist targets in Iraq and Syria.

The humanitarian agency is the guardian of the Geneva Conventions that lay down the rules of war, primarily aimed at protecting civilians caught up in armed conflicts.

Robert Mardini, head of ICRC operations for the Near and Middle East, asked about air strikes on Syria, told Reuters Television: "What is extremely important for us is that whatever country takes part in the hostilities has to comply with the basic rules and principles of international humanitarian law. ...

"The situation in Syria and in Iraq is already extremely difficult for the civilian population after years of conflict and a lot of destruction and impact on the lives of hundreds of thousands of civilians who are constantly on the move, who have had their belongings and houses destroyed, who have difficulties to access health care facilities and basic services ranging from water supply and sanitation to food supplies. So the situation is already dire," Mardini said.