Thousands of police have been deployed in Hiroshima and security tightened for the summit, but hundreds of anti-war demonstrators have staged rallies in Hiroshima in the lead-up to the three-day event, carrying banners reading “No nuclear war!” and “No imperialist G7 summit!”

On Thursday, members of animal rights group PETA donned face masks of the G7 leaders to urge governments to lead their societies away from eating meat.

“Animal agriculture is an existential threat to the planet and every species on it, and the only remedy is to go vegan,” said PETA Executive Vice President Tracy Reiman. “PETA urges G7 attendees and other world leaders to help head off the climate catastrophe while they still can by promoting vegan living.”

Other organisations are using the summit to urge governments to improve their preparedness for the next pandemic, or boost humanitarian assistance to the developing world.

Protests are a common sight at G7 summits, where the presence of the world’s media gives advocacy groups an opportunity to raise awareness of their cause in front of a global audience.

China’s President Xi Jinping has stressed Central Asian countries should oppose “external interference” in their internal affairs and attempts to instigate “colour revolutions” in a veiled swipe at liberal democracies such as the US.

Speaking at an unprecedented summit of regional nations in the historic Chinese city of Xian, Xi promised China would help Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan boost their economic development, and said it was also “ready to help Central Asian countries improve their law enforcement, security, and defence capability construction.”

The two-day summit coincides with the G7 where leaders will be discussing how to deal with an increasingly assertive China, which the US has accused of coercive diplomacy.

Xi’s gathering of five heads of state on Chinese soil without Russia also ostensibly pulls Central Asia closer to the Chinese sphere of influence with Moscow focussed on its war in Ukraine.

The Group of Seven (G7) is an informal group of leading industrialised democracies with no permanent secretariat or legal status.

The group held its first meeting in 1975 as their leaders struggled to deal with the oil crisis. Its members inlclude Canada, France, Germany, Italy, Japan, the United Kingdom and the United States.

Seen as a forum for the world’s richest nations to discuss global issues, its countries have a combined annual gross domestic product (GDP) of $40 trillion – making up just under half the world economy.

Reuters news agency has more on Zelenskyy’s possible trip to Japan.

It says the Ukrainian president will travel to Hiroshima on Sunday so he can join the summit in person.

That’s from a European Union source who did not want to be identified because the plan was not public.

As well as Ukraine, G7 leaders will be putting their heads together to discuss how they can respond to an increasingly assertive China.

The United States has been pushing a firmer line, but others are reluctant.

“The G7 is somewhat divided with Germany, as Europe’s industrial powerhouse, very eager to maintain and even expand ties with China. And at the same time we have China’s Xi Jinping holding, in a sense, a competing summit for central Asian leaders of state,” Hillary Mann Leverett, the chief executive of political consulting firm Stratega, told Al Jazeera from Washington, DC.

“That’s a very important summit because central Asia is the bridge between China and Europe, and China is increasingly focussed on Europe, which could create a wedge between Europe and the United States.”

Bloomberg News is reporting Ukrainian President Volodymyr Zelenskyy will travel to Japan to attend the G7 summit in person.

Zelenskyy’s physical attendance would be a surprise after the Japanese government last week told local media that the Ukrainian leader would only attend talks on Sunday online.

Bloomberg cited people familiar with the plans in its report.

Al Jazeera has not been able to independently confirm the plan.

Ukraine’s presidential office on Thursday told Japan’s Kyodo News that Zelenskyy’s attendance had not been ruled out and would depend on the “situation on the battlefield.”

A sombre moment in Hiroshima just now as the G7 leaders laid wreaths of white flowers at the memorial to those who died as a result of the nuclear bomb.

They stood in front of the memorial built in 1952 – the ruined shell of the A Bomb Dome behind – and bowed their heads.

Some 140,000 people were killed instantly when the bomb was dropped by the Enola Gay, but many more died afterwards because they couldn’t get the medical treatment they needed.

The explosion also created a massive fire that tore through the city, made up then mainly of wooden buildings, while others died months and years later from radiation poisoning,

Their names are inscribed on a register below the memorial, which carries the words: “Let all the souls here rest in peace, for we shall not repeat the evil.”

A key topic on the G7 agenda is how to put more pressure on Russia to end its war in Ukraine.

Western countries – and some other democracies including South Korea and Japan – have already imposed some of the toughest sanctions ever devised, but leaders in Hiroshima are expected to tighten the screws still further.

According to Rachel Lukasz, a member of the International Working Group on Russian Sanctions at Stanford University, there is “definitely plenty of space” for further action.

Find out more about the issue here.

We’re already seeing some of the sanctions coming into view.

A senior official with the administration of US President Joe Biden has told reporters that Washington plans 300 new sanctions targeting 70 Russian entities and place more countries on a US blacklist.

As well as the diamond ban, British Prime Minsiter Rishi Sunak says the UK will also ban imports of Russian copper, aluminium and nickel, and impose sanctions on 86 people and companies linked to Russian President Vladimir Putin.

China is a big issue as the G7 leaders meet in Japan, with some calling for a tougher line.

But European Council President Charles Michel has stressed it is in the European Union’s interest to maintain “stable and constructive” cooperation with China.

Michel was speaking on the sidelines of the Hiroshima summit.

He says the EU will urge China to step up pressure on Russia to stop its military aggression in Ukraine.

The G7 members take it in turns to host the group’s annual summit often choosing beach resorts or historically important cities.

Japan’s Prime Minister Fumio Kishida has gone for the latter.

On August 6 1945, the United States dropped the atomic bomb on Hiroshima, levelling the city and killing thousands of people.

The evidence of the nuclear blast are clearly visible and Kishida will formally welcome the leaders to the summit at the Hiroshima Memorial Peace Park. The area was the commercial and political heart of the city before the bombing and today only the ruined shell of the Atomic Bomb Dome remains, a haunting reminder of the destructive power of nuclear weapons.

For Kishida, committed to a nuclear weapons-free world, it is all about conveying “the reality” of an atomic attack. You can read more in this analysis from Al Jazeera’s John Power, who is in Hiroshima.

The leaders of the Group of Seven are gathering at the Hiroshima Peace Memorial Park  for the formal opening of the three-day summit.

Japanese Prime Minister Fumio Kishida is greeting the G7 leaders one by one as they arrive at the park, which commemorates the 140,000 people who are estimated to have died when the United States dropped the atomic bomb ‘Little Boy’ over the city on August 6, 1945.

Kishida, whose electoral seat is in Hiroshima, is a long-time advocate against nuclear weapons and plans to use the G7 summit to amplify his message about the need to work toward a nuclear-free world.

After being welcomed by Kishida, the G7 leaders are expected to lay wreaths at the cenotaph for the victims of the nuclear bomb.

Russia’s diamond industry is in the sights of the G7 leaders.

British Prime Minister Rishi Sunak is to announce a ban on Russian diamonds, according to a UK government statement.

The Financial Times is reporting other countries will join the ban, as the G7 tries to cut off the diamond industry’s revenues.

Citing draft G7 statements, the business paper says there are plans for a “traceability” initiative that would create a system for tracking individual gemstones. There isn’t one at the moment.

Russia’s state-owned diamond company Alrosa is already subject to sanctions.