US Defense Secretary Lloyd Austin on Monday vowed the US would take "all necessary actions" to defend its troops after a deadly drone attack in Jordan by Iran-backed militants, even as President Joe Biden's administration stressed it was not seeking a war with Iran.

"We do not welcome any actions that lead to destabilisation in the region and increase tensions, especially against the backdrop of the excessive potential for conflict," Kremlin spokesman Dmitry Peskov told reporters. 

"We will not welcome the continuation of such actions, regardless of who they come from. The level of tension is high now and we need to take steps to de-escalate. This is what will prevent the conflict from spreading."

Russia enjoys increasingly close ties with Iran at a time when its ties with the United States are at their lowest level since the 1962 Cuban missile crisis over what Moscow calls its "special military operation" in Ukraine.

Meanwhile, China on Tuesday warned against a "cycle of retaliation" in the Middle East after the United States vowed to respond to the drone attack.

Beijing said Tuesday it had "noted reports of casualties caused by the attack on a US military base".

"We have also noted that Iran stated that it had nothing to do with the attack," foreign ministry spokesperson Wang Wenbin said.

"We hope that all relevant parties will remain calm and restrained... in order to avoid falling into a vicious cycle of retaliation and prevent further escalation of regional tension," he added.

"The situation in the Middle East is currently highly complex and sensitive," Wang said.