MOSCOW -- Russian President Vladimir Putin and his US counterpart Donald Trump had discussed the situation in the Middle East in a phone conversation, the Kremlin said Saturday.

"The conversation lasted for 50 minutes, it was substantive, sincere and very useful," Russian Presidential Aide Yuri Ushakov said. "Naturally, it was focused on the dangerous exacerbation of the situation in the Middle East."

Putin denounced the Israeli military operation against Iran and expressed grave concern over the possible escalation of the conflict, which would have unpredictable consequences for the entire Middle East region, he said in a statement.

"Putin emphasized the importance of preventing the conflict from escalating and the readiness of the Russian side to engage in possible mediation efforts," he said.

Trump also views the situation as very alarming, he said, adding that the Russian and US presidents do not rule out a return to the negotiating track on Iran's nuclear program.

Trump noted that the team of US negotiators is ready to resume work with Iranian representatives, according to Ushakov.

Putin also informed Trump about the execution of the agreements reached by the Russian and Ukrainian delegations in Istanbul on June 2 and expressed readiness to continue talks with the Ukrainian side after June 22, he said.

Trump took note of this information and reiterated his interest in bringing the Russian-Ukrainian conflict to a speedy conclusion, he added.