Britain's Prime Minister Liz Truss promised on Tuesday to offer Ukraine at least £2.3 billion ($2.6bn) in military support next year, as she re-entered the political arena after the mourning period for Queen Elizabeth.
Ms Truss arrived in New York early on Tuesday for this week's UN General Assembly, her first foreign visit as prime minister, during which she will meet leaders including US President Joe Biden and French President Emmanuel Macron.
She promised that Britain would match or exceed the £2.3bn support it has given to Ukraine this year, with aid expected to include more of the multiple-launch rocket systems credited with powering a counter-offensive against Russia.
Military aid continued quietly during the mourning period, with ammunition sent to the front lines last week in what Downing Street described as one of the biggest shipments since the Second World War.
Ms Truss's address to the general assembly is expected to say that there will be “no let up” in Britain's military, political and humanitarian support to Ukraine.
She praised the success of President Volodymyr Zelenskyy’s troops in seizing back about 3,000 square kilometres of land that had been captured by the Russians.
“Ukraine’s victories in recent weeks have been inspirational,” she said. “Time and time again these brave people have defied the doubters and showed what they can do when given the military, economic and political support they need.”
Britain has been the second-largest military donor to Ukraine since January, behind only the US, according to a tracker maintained by the Kiel Institute for the World Economy.
With the related energy crisis set to dominate her first months in office, Ms Truss plans to lobby fellow world leaders and company chiefs in New York to speed up efforts to loosen Russia's grip on the power grid.
“By turning off the taps of the Nord Stream gas pipeline, Putin has consigned millions of people in Europe to a colder and more difficult winter,” she said.
Ukraine war latest — in pictures
But her talks with Mr Macron and Mr Biden may be overshadowed by differences of opinion over post-Brexit trade, its effects on the Northern Ireland peace process and other tensions with France.
Both leaders attended the state funeral in London and were warm in their tributes to the queen, but have expressed concern over Ms Truss's plans to set aside a UK-EU trade protocol on Northern Ireland.
Speaking to journalists on the plane to New York, Ms Truss was downbeat on the prospects of a UK-US trade deal, an issue that some American politicians have linked to the situation in Northern Ireland.
“There aren’t currently any negotiations taking place with the US and I don’t have an expectation that those are going to start in the short to medium term,” she said.
The prime minister said she wanted a “constructive relationship” with France, after her recent remark — that “the jury's out” on whether Mr Macron was a friend or a foe — compounded cross-Channel tension.
“Of course, that means working together on the issue of migration,” Ms Truss said. “There are a number of other issues we need to work together on, whether it’s energy security, whether it’s other issues relating to our relationship with the EU — but most importantly, it is ensuring that Putin does not succeed in Ukraine.”
The royal mourning period called a political truce in Britain only two days after Ms Truss had taken office, overshadowing her announcement that energy bills would be frozen at £2,500 ($2,860) for a typical UK household until 2024.
Chancellor of the Exchequer Kwasi Kwarteng is expected to offer more details of the government's economic plans in an emergency budget on Friday.
The opposition Labour Party is calling for the costly bailout to be financed by a windfall tax on energy companies, an idea rejected by Ms Truss.
Despite the energy squeeze, Ms Truss said rationing was not on the cards and declined to tell households they should go easy on heating this winter.
"There is a strong incentive for businesses and households to invest in energy efficiency, but we do have reliable supplies of energy - but ultimately everyone makes their own decisions about how they decide to do those things," she said.