As Witkoff and Kushner were negotiating at the Kremlin, Zelensky said he was ready for “a substantive conversation”.

Saturday’s talks in Moscow lasted three hours and were held behind closed doors in Putin’s official residence in the heart of the Russian capital, according to Russian state media.

Details are still emerging, but both sides have given broadly positive remarks without going into specifics.

Putin adviser Yuri Ushakov described the talks as “constructive, extremely frank”.

“The talks were not limited to an exchange of views on resolving the Ukrainian crisis – economic issues and potential major, mutually beneficial Russian-American projects were discussed in considerable detail,” he said.

Ushakov also said “note was made of the Russian army’s tangible advances in the combat zone” and that there was acknowledgement that talks needed to address “the root causes of the conflict”.

Despite an escalation of Russian missile and drone strikes on Ukrainian cities including Kyiv, Russian ground forces have made very slow advances for most of the conflict, incurring enormous casualties. Russia still controls about one-fifth of Ukrainian territory – areas that it seized back in 2022.

Kushner and Witkoff have visited Russia several times but given Ukraine’s airspace has been closed since Russia launched its full-scale invasion in February 2022, it is not clear how they will be travelling to Kyiv from Moscow.

The talks come after Russia and Ukraine have intensified aerial attacks in recent months.

Ukraine says it has struggled to repel ballistic missile attacks due to a lack of interceptor missiles, while Kyiv has focused its strikes on Russian economic infrastructure targets, notably oil installations.