The talks in Jeddah on Saturday and Sunday will be led by Saudi National Security Adviser and Minister of State Musaed al-Aiban, who extended the "secret invitations" during a meeting organised by Ukraine in Denmark in June, the sources told the DPA news agency.
Officials from the United States, European countries, Turkey and Egypt are expected to take part.
Russia, however, will not attend.
A Kremlin spokesman said that Russia will monitor the meeting.
The gathering will discuss a peace plan put forward by Ukrainian President Volodymyr Zelenskiy late last year.
Sources said there are Saudi efforts to find a compromise accepted by both sides, with the hope that "a global peace summit" to end the war could be held later this year.
Russia's says the US and European countries must recognise territories it annexed from Ukraine before it will enter into negotiations - a demand rejected by Ukraine's allies.
Saudi Arabia has repeatedly offered to mediate between Russia and Ukraine.
Last year, officials in Riyadh said they helped with the release of prisoners of war.
The oil-rich kingdom and its Gulf neighbours have so far resisted US-led pressure to cut ties with Russia since it launched its full-scale invasion of Ukraine more than 17 months ago.
Meanwhile, Russia's defence ministry said on Tuesday it had thwarted attacks by Ukrainian sea drones on its navy and civilian ships in the Black Sea and a local governor said authorities had also downed a drone over the Crimean city of Sevastopol.
Ukraine denied that it had attacked civilian ships, without directly addressing the claim that it had attacked Russia's navy.
"During the night the armed forces of Ukraine made an unsuccessful attempt to attack the Sergei Kotov and Vasiliy Bykov patrol ships of the Black Sea fleet with three unmanned sea boats," Russia's defence ministry said in a statement.
It said the two ships were controlling shipping 340km southwest of Sevastopol and would continue to perform their duties.
Later, in its daily briefing, the ministry said navy ships had destroyed three more sea drones targeting civilian vessels.
"During the night, the Kyiv regime attempted a terrorist attack with three semi-submersible unmanned boats on Russian civilian transport vessels heading towards the Bosphorus Strait in the southwestern part of the Black Sea," the ministry said.
On Tuesday evening, Russia downed a drone over a district of Sevastopol, local governor Mikhail Razvozhaev said on the Telegram messaging app.
He said the downing caused an explosion on the ground and some bushes caught fire.
Ukrainian presidential official Mykhailo Podolyak told Reuters: "Undoubtedly, such statements by Russian officials are fictitious and do not contain even a shred of truth. Ukraine has not attacked, is not attacking and will not attack civilian vessels, nor any other civilian objects."
Russia has said it would treat any ships leaving or entering Ukrainian ports as valid targets after the expiration of a United Nations-backed deal last month which had allowed for exports of Ukrainian grain via the Black Sea.
Ukraine has previously used drones to target Russia's navy base in Crimea and the bridge that Russia has built to the peninsula.
with Reuters
