MOSCOW (Reuters) -The Kremlin said on Monday it needed to learn more about the purpose of talks planned in Saudi Arabia about the war in Ukraine, but Ukraine made it plain Russia was not welcome at the meeting.

The meeting was first reported last Saturday in the Wall Street Journal, which said Saudi Arabia would invite Western states, Ukraine and major developing countries to talks focusing on Ukrainian President Volodymyr Zelenskiy's peace plan.

The paper said Kyiv and Western countries hoped that the talks could lead to international backing for peace terms favouring Ukraine.

Asked about the WSJ report, Kremlin spokesperson Dmitry Peskov said: "Of course, Russia will follow this meeting. We need to understand what goals are set and what will be discussed. Any attempt to promote a peaceful settlement deserves a positive evaluation."

Peskov, however, also restated Moscow's position that it currently saw no grounds for peace talks with Kyiv.

"The Kyiv regime does not want and cannot want peace, as long as it is used exclusively as a tool in the war of the collective West with Russia," he said on a call with reporters.

Mexican President Andres Manuel Lopez Obrado said he was willing to attend provided both Russian and Ukrainian representatives were present.

"If there's acceptance from both Ukraine and Russia to look for solutions to achieve peace, we'll participate," he told reporters in Mexico City. "We don't want the Russia-Ukraine war to continue, it's very irrational."

Andriy Yermak, Zelenskiy's chief of staff, said Ukraine would be "boundlessly happy if West, East, South and North work in this format towards renewing a system of world security".

"But this is a forum of responsible states who stand by international rights and the U.N. statutes. And that's why Russia won't be there," Yermak wrote on Telegram alongside a dispatch on the Mexican president's remarks.

Saudi Crown Prince Mohammed bin Salman has previously expressed a readiness to mediate in the conflict.

Russian President Vladimir Putin said on Saturday that an African initiative - calling for confidence-building measures followed by a cessation of hostilities - could be a basis for peace but that Ukrainian attacks on Russia made this hard to realise.

Zelenskiy's plan, proposed earlier this year, calls for the withdrawal of all Russian troops and restoration of Ukraine's post-Soviet borders. He rejects any notion of a ceasefire that would leave Russia in control of nearly a fifth of his country and give its forces time to regroup after 17 months of war.

(Reporting by Reuters; Writing by Gareth Jones; Editing by Ron Popeski and Stephen Coates)