By Fransiska Nangoy and Stanley Widianto

NUSA DUA, Indonesia (Reuters) -Leaders of the Group of 20 (G20) nations were considering a draft resolution on Tuesday in which most members strongly condemn the war in Ukraine and stress it is exacerbating fragilities in the global economy, diplomats said.

"There were other views and different assessments of the situation and sanctions," said the 16-page draft declaration, a copy of which was seen by Reuters. It has not been adopted by the leaders and is likely to be opposed by Russia.

A decision on the resolution was unlikely before Wednesday, diplomats said.

"Recognising that the G20 is not the forum to resolve security issues, we acknowledge that security issues can have significant consequences for the global economy," the draft said.

G20 ministers' gatherings in the past have failed to produce joint declarations due to disagreement between Russia and other members on language, including on how to describe the war in Ukraine.

The summit, being held on the Indonesian island of Bali, marks the first time G20 leaders are meeting since Russia's February invasion of Ukraine, which Russia has described as a "special military operation".

The war and worries over global inflation, food and energy security have overshadowed the meeting.

Earlier, Ukrainian President Volodymyr Zelenskiy told the summit in a virtual address that now was the time to stop Russia's war in his country under a plan he has proposed "justly and on the basis of the U.N. Charter and international law".

He called for restoring "radiation safety" with regard to the Zaporizhzhia nuclear power plant, introducing price restrictions on Russian energy resources, and expanding a grain export initiative.

"Please choose your path for leadership - and together we will surely implement the peace formula," he said.

The summit opened with a plea by Indonesian President Joko Widodo for unity and concrete action to mend the global economy despite deep rifts over the war.

"We have no other option, collaboration is needed to save the world," he said. "G20 must be the catalyst for inclusive economic recovery. We should not divide the world into parts. We must not allow the world to fall into another cold war."

The G20, which includes countries ranging from the United States, Russia and Brazil to India, Saudi Arabia and Germany, accounts for more than 80% of the world's gross domestic product, 75% of international trade and 60% of its population.

Russia's invasion of Ukraine triggered calls by some Western leaders for a boycott of the summit and for the withdrawal of Russian President Vladimir Putin's invitation, but Indonesia resisted and refused to do so.

Russia has said Putin was too busy to attend and Foreign Minister Sergei Lavrov is taking his place. Lavrov dismissed a news agency report on Monday that he had been taken to hospital in Bali with a heart condition and was present at the meeting.

He remained in the room while Zelenskiy made his address, delegates said.

CHINA FAVOURS CEASEFIRE

On the eve of the summit, U.S. President Joe Biden and Chinese leader Xi Jinping held a three-hour bilateral meeting in which the two leaders pledged more frequent communications despite many differences.

The meeting was the first the two had in person since Biden became president and it appeared to signal an improvement in relations between the superpowers after a downward spiral in recent months.

Xi and Putin have grown increasingly close in recent years, and reaffirmed their partnership just days before Russia invaded Ukraine. Nevertheless China has been careful not to provide any direct material support that could trigger Western sanctions against it.

On Tuesday, Xi told French President Emmanuel Macron during a bilateral meeting that China advocated a ceasefire in Ukraine and peace talks, Chinese state media reported.

Biden and Xi "underscored their opposition to the use or threat of use of nuclear weapons in Ukraine" during their meeting, the White House said.

Xi told Biden nuclear weapons cannot be used and nuclear wars cannot be fought, the Chinese foreign minister said in a statement.

The West has accused Russia of making irresponsible statements on the possible use of nuclear weapons since its invasion of Ukraine. Russia has in turn accused the West of "provocative" nuclear rhetoric.

On the summit's sidelines, many of the leaders will hold bilateral talks, with several of them meeting Xi, who is making only his second visit overseas since the beginning of the coronavirus pandemic.

After the meeting with Macron, Xi is scheduled to hold talks with Australian Prime Minister Anthony Albanese, South Korean President Yoon Suk-yeol and, later in the week, with Japanese Prime Minister Fumio Kishida as China tries to reduce frictions with the United States and its allies.

"It is not decisive but an important step towards trying to reduce disagreements," Shi Yinhong, a professor of international relations at Beijing's Renmin University, said of Xi's meetings at the gathering.