KYIV, Aug 5 (Reuters) - Talks starting Saudi Arabia this weekend to find a peaceful settlement to end Russia's war in Ukraine will be difficult, but Kyiv is counting persuading more countries to back its peace formula, the head of Kyiv's delegation said on Friday.

Ukraine and its allies hope the meeting in Jeddah of national security advisers and other senior officials from some 40 countries - but not Russia - will agree on key principles on how to end Russia's war in Ukraine.

"I expect that the conversation will be difficult, but behind us is truth, behind us - goodness," Andriy Yermak, head of President Volodymyr Zelenskiy's office and his key envoy for the talks, said late on Friday in a television interview published on his Telegram messaging app.

The forum excludes Russia, but the Kremlin said it will "keep an eye" on the meeting. China, which has firm ties with Russia, said on Friday it will send Special Envoy for Eurasian Affairs Li Hui for the talks.

"We have many disagreements and we have heard different positions, but it is important that our principles are shared," he said.

Ukrainian, Russian and international officials say there is no prospect of direct peace talks between Ukraine and Russia at the moment, as the war continues to rage and Kyiv seeks to reclaim territory through a counter-offensive.

But Ukraine aims first to build a bigger coalition of diplomatic support beyond its core Western backers by reaching out to Global South countries such as India, Brazil and South Africa, many of which have remained publicly neutral.

Zelenskiy said he hoped the initiative will lead to a "peace summit" of world leaders this autumn to endorse the principles, based on his own 10-point formula for a settlement. Moscow has rejected Zelenskiy's peace formula.