G7 to squeeze Russia, weigh risk of China's 'economic coercion'

G7 leaders arrived in Hiroshima, Japan, on Thursday to weigh tighter sanctions on Russia and protections against China's "economic coercion", surrounded by reminders about the harrowing cost of war.

Japanese Prime Minister Fumio Kishida is hosting leaders from six other wealthy democracies in his hometown -- a city synonymous with nuclear destruction and now peppered with peace monuments.

Leaders including US President Joe Biden will try over three days to forge a united front on Russia and China, where the allies' interests do not always neatly align.

Biden's delicate diplomatic offensive in Asia hit a bump even before Air Force One left US soil: a domestic budget row forced him to cancel stops in Papua New Guinea and Australia.

He arrived in Hiroshima Thursday, becoming just the second US president after Barack Obama to visit a city levelled by his country's "Little Boy" atomic bomb.

Russia's 15-month-old invasion of Ukraine will top the agenda when the G7 summit gets underway Friday, after a new spate of aerial attacks on Kyiv and a long winter of grinding warfare in Bakhmut and other frontline towns.

"We stand up for the shared values including supporting the people of Ukraine as they defend their sovereign territory and holding Russia accountable for its brutal aggression," Biden said as he met Kishida Thursday.

The United States and its allies have poured weaponry into Ukraine to stall the Russian advance, but a long-anticipated spring counteroffensive by Kyiv's forces has yet to materialise.

Ukrainian President Volodymyr Zelensky is expected to address the group by video link.

US National Security Advisor Jake Sullivan said leaders would discuss battlefield developments and tightening a sanctions regime that, according to official statistics, caused Russia's economy to contract a further 1.9 percent last quarter.

G7 nations have already adopted sanctions on Russian banks and military firms, and placed price caps on Russian crude.

Discussions are expected on tighter enforcement, and new measures on a range of goods, including Moscow's roughly $5 billion annual trade in diamonds.

- Nuclear shadow -

Putin's repeated threats to turn the Ukraine conflict nuclear have been roundly condemned by G7 leaders and dismissed by some commentators as little more than an attempt to shake European and American resolve.

But a leaders' visit to the Hiroshima Peace Memorial Park on Friday is likely to pull those threats into sharper focus.

The bombing on August 6, 1945, obliterated Hiroshima, claimed an estimated 140,000 lives and forever changed the world. 

Kishida wants to use the summit to press his guests -- nuclear powers Britain, France and the United States -- to commit to transparency on stockpiles and arsenal reductions.

But expectations for a breakthrough are low.

- 'Economic coercion' -

Summit discussions on China are expected to focus on efforts to insulate G7 economies from potential economic blackmail, by diversifying supply chains and markets.

In disputes with countries from Australia to Canada, President Xi Jinping's administration has shown a willingness to block, tax or hamper trade with little warning or explanation.

White House official Sullivan said leaders were expected to decry this "economic coercion" and work to bridge transatlantic differences about how to engage with China.

Washington has taken an aggressive approach, blocking China's access to the most advanced semiconductors and the equipment to make them, and has pressed Japan and the Netherlands to follow suit.

But European policymakers -- most notably those in Berlin and Paris -- are keen to make sure that "de-risking" does not mean shattering ties with China, one of the world's largest markets.

"This G7 is not an anti-Chinese G7," an adviser to French President Emmanuel Macron told journalists before the summit.

"We have a positive message for China, which is that we are ready to cooperate on condition that we negotiate together," the adviser added.

Host Japan is also keen to talk to developing nations that have been wooed by Chinese investment, with leaders from India, Brazil and Indonesia among those invited by Kishida to Hiroshima.

Evidence of Beijing's growing economic and diplomatic clout was on display Thursday in the former imperial capital Xi'an.

There, Xi is hosting the leaders of five Central Asian countries that were once seen as firmly in Moscow's orbit but are increasingly drawn to Beijing.