By Michel Rose, John Irish and Steve HollandEvian-les-Bains, France — US President Donald Trump on Wednesday told a roomful of global leaders, “I’m the boss,” as he and other G7 heads acknowledged Ukraine’s improved battlefield fortunes with a unified pledge of support and fresh sanctions against Russia.Trump’s comment — a tongue-in-cheek acknowledgement of an unspoken truth hanging over the June 15 to 17 summit of the Group of Seven Western powers in the French resort of Evian-les-Bains — followed a joint leaders’ statement that could bolster Kyiv’s growing leverage in potential peace talks with Moscow.Ukrainian President Volodymyr Zelensky and his allies came to the G7 hoping to convince Trump that Ukraine’s fightback is delivering results and that Russia is in no position to dictate terms for any peace deal.The joint statement and comments from leaders suggest Trump has warmed to Zelensky’s argument after years of scepticism. This showed a “real change in approach” from the US regarding the Ukraine war, Macron said, calling the summit a “success”. A G7 summit in Canada last year ended without any joint stance on Ukraine.Common groundItalian Prime Minister Giorgia Meloni said leaders “found common ground [with Trump], and that can’t always be taken for granted”, while Canada’s Mark Carney praised “a change in position on the part of the US and President Trump”.Last year Trump had left the G7 summit a day early due to the situation in the Middle East, and leaders seemed relieved he had stayed till the end this time — ahead of a glitzy dinner in the Palace of Versailles later in the day — and had agreed to several joint statements, from Ukraine to AI and critical minerals.However, any hopes of strongarming Moscow into peace talks still rely on Trump commitments, which can be elusive.“I’m the boss,” Trump told G7 chiefs and reporters as he arrived to take his seat at a session on global economic security.Trump stressedG7 chiefs also welcomed a preliminary peace deal between the US and Iran and said they were ready to help implement it but left with no commitment from Trump on what their role, if any, could be.European allies fear an inexperienced US negotiating team may fail to secure a robust nuclear agreement or address Iran’s ballistic missile programme in the next phase, risking a prolonged standoff.Meanwhile, Trump stressed that the memorandum of understanding with Iran was not final and that he could resume a bombing campaign if it was not honoured.“If I don’t like it, if they don’t behave, we’ll go right back to dropping bombs right smack in the middle of their head, OK?” he said.And although European allies appeared supportive of the preliminary memorandum in public, diplomats cautioned that getting a lasting deal on Iran’s nuclear and ballistic missile programme as well as its support for proxy forces in the Middle East is no small challenge.Western powersSeparately, G7 leaders agreed to step up co-ordination to cut their countries’ reliance on China for critical minerals, including plans to align stockpiling and launch a new platform with an expanded role for the International Energy Agency.Western powers are racing to diversify their sources of metals critical to defence, tech and renewable energy and reduce their over-reliance on China for these products.G7 leaders also discussed AI over lunch, including the liability of bots and agents and how AI presents truth and falsehood with tech bosses, including OpenAI co-founder Sam Altman and Anthropic CEO Dario Amodei.