A joint statement issued by Russia, Iran, and their allies in Syria denounced the U.S. missile strike on a Syrian airbase said to have launched a chemical weapons attack on Syrian civilians and threatened retaliation if further such attacks occur.

“The United States crossed red lines by attacking Syria, from now on we will respond to anyone, including America if it attacks Syria and crosses the red lines. America knows very well our ability and capabilities to respond well to them, [and] we will respond without taking into consideration any reaction and consequences,” read the statement, as transcribed by ABC News.

“Rest assured that we will liberate Syria from all kinds of occupying forces, it does not matter from where they came to the occupied part of Syria,” the statement added. “Russia and Iran will not allow the United States to be the only superpower in world.”

According to the statement, Syria and its patrons are “closely and deeply following American forces’ moves and presence” in both Syria and Iraq and “consider them an occupying force.”

Russia and Iran stated, “we, as Syria’s allies, will increase our military support toward Syria and support its people in many other ways.”

On Friday, Russia suspended military cooperation with the United States in Syria, including an end to the “deconfliction” agreement that was meant to prevent accidental hostile encounters between Russian and American pilots.

“Amid the missile strikes, it is hardly reasonable to talk about any more increase in the risk, as the risk has increased considerably,” said Kremlin spokesman Dmitry Peskov.

Over the weekend, Iranian president Hassan Rouhani urged “the Syrian people and army” to “give a response that makes Americans regret their attack.”

“Americans have never acted within international frameworks, and one instance is the sanctions they impose against Iran, unreasonably considering themselves as the world’s leader,” complained Rouhani, who was hailed as a “moderate” leader by the Obama administration.

Al-Jazeera notes that Lebanon’s Hezbollah, designated a terrorist organization by the U.S. State Department, was a signatory to the Russian-Iranian statement.