Ukraine's prime minister has told the BBC there will be a "Third World War" if Ukraine loses its conflict with Russia, as he urged the US Congress to pass a long-stalled foreign aid bill.

Denys Shmyhal expressed "careful optimism" that US lawmakers would pass the hotly contested measure, which has $61bn (£49bn) earmarked for Kyiv. The House of Representatives is set to vote on the package this Saturday.

The proposal includes funding for Israel as well as the Indo-Pacific. Speaking to the BBC in Washington DC on Wednesday, Prime Minister Shmyhal said of the US security assistance: "We need this money yesterday, not tomorrow, not today."

"If we will not protect... Ukraine will fall," he added. "So the global, the global system of security will be destroyed... and all the world will need to find... a new system of security.

"Or, there will be many conflicts, many such kinds of wars, and in the end of the day, it could lead to the Third World War."

This is not the first time Ukraine has issued such an alarming warning about the consequences of its potential defeat.

Last year, President Volodymyr Zelensky said that if Russia won the conflict, it could next invade Poland, triggering World War Three.

But Kremlin officials have ridiculed such claims as Western scaremongering. Last month President Vladimir Putin dismissed suggestions that Russia might one day attack Eastern Europe as "complete nonsense".

Russia has never attacked a country within Nato, which includes Poland. Nato's collective defence pact means that an attack on one member constitutes an attack on all.

In Wednesday's interview, Prime Minister Shmyhal was asked about a recent claim by Republican House Foreign Affairs Chairman Michael McCaul that members of his own party were being "infected" by Russian propaganda.

Mr Shmyhal said: "We should understand that disinformation and propaganda is influencing here in the United States on many people, in European Union on many people, such as in Ukraine."

Opposition from the right wing of the Republican party has blocked potential assistance to Ukraine for months.

(Source: BBC)