US President Donald Trump's special envoy Steve Witkoff has arrived in Russia, the RIA state news agency reported on Friday, citing the Kremlin.

Axios earlier reported, citing a source familiar with the trip and FlightRadar data, that Witkoff had travelled to Russia and was expected to meet President Vladimir Putin on Friday.

The visit comes a week after Kirill Dmitriev, head of Russia's sovereign wealth fund and President Vladimir Putin's special envoy on economic cooperation, met Witkoff and other US officials in Washington.

Russia characterised the last Putin-Witkoff meeting as positive, saying the Russian president listened to the envoy and conveyed key information for Trump through him.

On Thursday, a US delegation arrived at the Russian Consulate General in Istanbul for talks to normalise embassy operations between the two countries.

The Russian delegation was led by Russia's Ambassador to the US, Alexander Darchiev, while the US delegation was led by Deputy Assistant Secretary Sonata Coulter.

Ahead of the meeting, Darchiev announced that some progress had already been made on several issues.

Both Moscow and Washington have complained in recent years about the difficulties of getting credentials for their diplomats, making the operation of their embassies extremely difficult.