Keir Starmer has urged Labour MPs to support his “unpopular” plan to remove the winter fuel allowance for all but the poorest pensioners, saying the government could not run away from difficult choices. Speaking in his first major TV interview since taking office, the prime minister also hinted at increased support for Ukraine, saying his visit to the White House next week to see President Biden would be focused on the “strategic” situation there, and in the Middle East. Asked about Tuesday’s vote on the changes to the fuel allowance, forced after the Conservatives submitted a motion to annul the government’s change to regulations, Starmer refused to say if Labour MPs who rebelled would be stripped of the whip – but made it clear he expected their support. “That will be a matter for the chief whip,” he told BBC One’s Sunday with Laura Kuenssberg. “We’re going into a vote. I’m glad we’re having a vote, because I think it’s very important for parliament to speak on this. But every Labour MP was elected in on the same mandate as I was, which was to deliver the change that we need for the country.” The new government has already suspended the Labour whip from seven MPs who supported an amendment in July to end the two-child benefits cap. Starmer stressed that restricting access to the payments was a vital part of reducing spending he said had spiralled under a Conservative government that had “run away from difficult decisions”. “I’m absolutely convinced that we will only deliver that change – I’m absolutely determined we will – if we do the difficult things now,” he said. “I know they’re unpopular, I know they’re difficult. Of course, they’re tough choices. Tough decisions are tough decisions. Popular decisions aren’t tough, they’re easy. “I do recognise how difficult it is for some people. I do recognise it’s really hard for some pensioners. But of course, they do rely on the NHS, they do rely on public transport. So these things aren’t completely divorced.” Worries about the impact of the policy change are known to be shared by some cabinet ministers, with some frontbenchers believing the government will have to announce extra support in the budget. Starmer, however, argued that with the triple lock policy of pension increases, he could guarantee that the annual increase in the state pension “will outstrip any reduction in the winter fuel payment”. Starmer is due to be in Washington on Friday for talks with Biden, a trip not yet set out by No 10 but announced by the White House. Asked if this was an attempt to assuage anger among US officials about the UK’s decision last week to suspend some arms export licences to Israel because of risks they could be used in violations of international law, Starmer rejected the characterisation. “You’re wrong about that,” he said. “We’ve been talking to the US beforehand and afterwards, and they’re very clear that they’ve got a different legal system, and they understand the decision that we’ve taken. So that’s very clear. “The reason I’m actually going and having the visit is not about that at all. It’s because the situation in Ukraine is becoming ever more pressing, as is the situation in the Middle East.” The talks with Biden would focus on “the tactical decisions we have to make” on those areas, he added, saying that the next few months would be crucial for Ukraine, as well as in the Middle East. Asked if this could lead to an increase in support for Ukraine, or a decision to allow Kyiv to use donated weapons on targets inside Russia, Starmer said he was “not going to get into a discussion about that on live television”. He added: “But of course, I want to make sure that we give Ukraine the support that it needs for as long as it needs.”