Former U.K. Prime Minister David Cameron on Thursday said he is fearful that U.S. President Donald Trump’s approach to securing peace in Ukraine could set an alarming precedent.

“My hope is that what Donald Trump is doing is using quite startling language and quite startling approaches to try and unlock situations, to try and create a situation where Ukraine wants to negotiate peace, Russia wants to negotiate peace, and to get there,” Cameron told CNBC’s CONVERGE LIVE in Singapore on Thursday.

“My fear is always that it goes beyond that [and] Trump’s view of the world is more that the big power in the neighborhood is sovereign, and you shouldn’t interfere with what they want to do,” Cameron said.

He said that could be “very worrying” for the Baltic states — Estonia, Latvia, and Lithuania — which, like Ukraine, all share a border with Russia.

“I think it’d be very worrying for Ukraine. These are independent, sovereign countries and we should support the idea that independent sovereign countries should not be invaded,” he added.

Cameron served as U.K. prime minister from 2010 to 2016 and as foreign minister in former Prime Minister Rishi Sunak’s government from 2023 to 2024.

His comments come shortly after Ukraine said it was ready to support the White House’s proposal for an immediate 30-day ceasefire if Russia accepts the plan. The U.S. on Tuesday agreed to resume military aid and intelligence sharing with Ukraine as part of the plan.

Russia launched its full-scale invasion of Ukraine more than three years ago.

Trump has alarmed European allies by appearing to turn toward Moscow, breaking with decades of U.S. foreign policy.

Russia’s onslaught in Ukraine has ratcheted up fears throughout the Baltic countries that they may be President Vladimir Putin’s next military target.

Even though the Baltic states have been part of NATO and the European Union since 2004, with all three using the euro as their currency, their geographic location makes them vulnerable.

Notably, while Estonia and Latvia share an eastern border with Russia, Lithuania shares a western border with the Russian exclave Kaliningrad.

“If we jump straight to the situation in Ukraine, I simply don’t accept that we should somehow say to Vladimir Putin: ‘Well, that’s your neighborhood, you can walk into any country you want, you can influence any country you want,'” Cameron said.

“The idea that a bully should be able to get away with what they want in their neighborhood. I don’t think that’s going to be good for Singapore, it certainly wouldn’t be good for Britain, and I don’t think it would be good for America either,” he added.

Away from Ukraine, Britain’s Cameron was asked for his views on a simmering global trade war, with uncertainty over Trump’s tariffs stoking concern on Wall Street.

“I’m worried about this because I’m a free trader. I believe that if you maximize free trade, it isn’t a one country wins and the other country loses, it can be a win-win situation and it normally is,” Cameron said.

“I fear that Donald Trump’s view of the world is he sort of looks at a country and says if you’ve got a surplus in trade with me, you’re ripping me off. That’s not the case. If every country in the world had a surplus, who would have the deficit? Mars, Jupiter? So, I don’t think that view of the world is right,” he continued.

“But, and it is an important but, as ever with Donald Trump, at the heart of what he is saying there is a real and understandable concern,” Cameron said.