Sir Keir Starmer will address world leaders at the UN General Assembly and woo US business chiefs as his visit to New York continues.

The gathering of world leaders at the UN comes as the Middle East teeters on the brink of all-out war and conflict rages in Ukraine.

The Prime Minister will use his speech to say the UK is returning to “responsible global leadership” because it is in British interests to address problems around the world.

“War, poverty and climate change all rebound on us at home. They make us less secure, they harm our economy, and they create migration flows on an unprecedented scale,” he will say.

His speech on Thursday follows an intervention at the UN Security Council on Wednesday where he tore into Russia over its actions in Ukraine, saying Vladimir Putin was treating his own citizens as “bits of meat to fling into the grinder” in the conflict.

He said Russia, which like the UK is one of the five permanent members of the Security Council, was behind the “greatest violation of the (UN) charter in a generation”.

“I wonder how Russia can show its face in this building,” he added.

The UN gathering comes as violence in the Middle East continues to escalate, with fighting between Israel and Hezbollah across the Lebanon border and a humanitarian crisis in Gaza.

On Wednesday, Sir Keir told the Security Council: “I’m calling for all parties to step back from the brink, to de-escalate. We need a ceasefire so this can be sorted out diplomatically.”

Starmer visit to New York
Prime Minister Sir Keir Starmer with Ukrainian President Volodymyr Zelensky (Leon Neal/PA)

He added that there can be “no more excuses” from Israel about humanitarian access to Gaza while Hamas must release the remaining hostages.

Alongside the diplomatic activity, Sir Keir is also meeting US business leaders to push for investment in the UK.

Investment giant Blackstone confirmed a £10 billion deal to develop Europe’s largest AI data centre in Blyth, Northumberland.

The firm’s president, Jon Gray, will be among the executives at a roundtable event hosted by Sir Keir on Thursday.

Other executives at the event include Adebayo Ogunlesi of Global Infrastructure Partners, Shemara Wikramanayake of Macquarie Group, Robin Vince of BNY, William Huffman of Nuveen, Brian Moynihan of Bank of America, Carlyle Group’s Harvey Schwartz, JPMorgan’s Mary Callahan Erdoes, Citigroup’s Jane Fraser and Brookfield Asset Management’s Hadley Peer Marshall,

This comes ahead of the UK’s international investment summit in October, which the Government hopes will attract hundreds of leading chief executives and financiers.