US Secretary of State Anthony Blinken. Photo: EPA

US Secretary of State Anthony Blinken suggested on Thursday that some Russia-occupied Ukrainian territories might have to be returned by diplomatic rather than military means, while reaffirming that any such decisions should be made by Kyiv.

"I think there's going to be territory in Ukraine that the Ukrainians are determined to fight for on the ground; there may be territory that they decide that they'll have to try to get back in other ways," Mr Blinken said in Congress during a hearing on the proposed budget.

He was responding to a question from Republican Representative Chris Stewart, who asked whether Joe Biden's administration supports President Volodymyr Zelensky of Ukraine in his efforts to retake Crimea, which was seized and annexed by Russia in 2014.

As the Utah lawmaker and a former B-1 strategic bomber pilot put it, "My great fear is not a recognition that Crimea is different than the eastern Donbas region."

"If our commitment and our agreement with Mr Zelensky is [that] we will support you whatever you want to achieve, including no Russian presence at all in Crimea, then we're asking for a world of hurt," Mr Steward added.

In response, the US Secretary of State emphasised that "these have to be Ukrainian decisions about what they want their future to be and how that lands in terms of the sovereignty, the territorial integrity, the independence of the country."

"What we don't want, for everyone's interests, is to have this settle in a place and in a way that simply invites the Russians to reset, rearm and then re-attack," Mr Blinken added.

Ukrainian officials have for some time suggested that Crimea would be retaken by the end of the year.

Kyrylo Budanov, the head of Ukraine’s defence intelligence, believes that the peninsula would be de-occupied by combined means of military force and diplomacy.

Kyiv’s plans have been met with scepticism and caution in Western capitals, which fear that such a move, which is of highly symbolic importance to President Vladimir Putin of Russia, might be met with further escalation on the battlefield.