The suspension of all US military aid to Ukraine has fulfilled Volodymyr Zelensky’s nightmare scenario, calling into question how long the country’s forces can hold out against Russia.

Throughout the war, Ukraine has been heavily dependent on Washington’s military largesse. Not only has the United States been by far Ukraine’s biggest single financial and military backer, it has provided weapons systems that no European state can match.

Despite the blow, and however grave the crisis and sense of betrayal in Ukraine, soldiers on the front line say they will continue fighting the Russian invaders for as long as they can.

Such claims are not just wishful thinking. Ukraine has increased domestic weapons manufacturing capacity. Its drones are becoming ever more sophisticated, helping to slow the Russian advance along the front, and also enabling Ukraine to strike critical infrastructure targets deep in Russian territory.

With other Western allies, including Britain, pledging to step up support there is some hope that, even if it suffers some territorial losses in the Donbas, Ukraine will be able to keep fighting at least until the summer, most analysts agree. How far beyond that it can survive is a much harder question to answer.

What will the immediate impact of the freeze be?

Since the start of the war three years ago, the United States has allocated more than $67 billion (£53 billion) in military aid, according to the Kiel Institute, a German think tank. In the final few months of his presidency, Joe Biden stepped up weapons deliveries to Ukraine, meaning that Kyiv’s stockpiles are reasonably healthy for the next few months.

Yet there will still be an immediate impact. More than $1billion in arms and ammunition that is either on order or in the process of being delivered will now not cross the Polish border until the pause on aid is lifted — if it ever is. Donald Trump, the US president, has indicated he will keep the freeze in place until he is convinced that Mr Zelensky is genuinely committed to negotiations with Russia, presumably on Mr Trump’s terms.