Donald Trump has threatened Vladimir Putin with crippling new sanctions, but requires Nato to take action first.

In a letter to Nato nations, the US President urged them to stop buying Russian oil and impose major sanctions on Russia to end its war in Ukraine.

Mr Trump wrote on his Truth Social: "I am ready to do major sanctions on Russia when all Nato nations have agreed, and started, to do the same thing, and when all Nato nations stop buying oil from Russia.

"As you know, Nato's commitment to win has been far less than 100 per cent, and the purchase of Russian oil, by some, has been shocking!"

The US President demanded Nato nations impose 50 to 100 per cent tariffs on China to weaken its economic grip over Russia.

Mr Trump continued: "China has a strong control, and even grip, over Russia, and these powerful tariffs will break that grip."

The 47th President issued earlier threats against Moscow and secondary sanctions on countries buying its oil, such as China and Russia.

He imposed an additional 25 per cent on Indian goods, citing its continued imports of Russian oil.

Mr Trump has called on Nato nations to impose a 50 to 100 per cent tariff on China

Mr Trump continued: "If Nato does as I say, the war will end quickly, and all of those lives will be saved.

"If not, you are just wasting my time, and the time, energy, and money of the United States."

The UK Government recently implemented 100 new sanctions aimed at hitting Russia's revenue and military supplies.

New foreign secretary Yvette Cooper announced the move as she journeyed to Kyiv.

Mr Putin has been accused of obstructing peace efforts following his talks with Mr Trump in Alaska, after launching a series of air attacks, including 800 missiles and drones in a single night.

The number of Russian drones and missiles has increased by 10-fold compared to a year ago, with 6,500 fired in July alone.

Recent strikes have struck the Ukrainian cabinet of ministers, the British Council and the EU delegation buildings in Kyiv.

Russia also fired "suicide drones" over Poland, temporarily shutting down the Nato ally's airspace.

Ms Cooper announced new sanctions imposed on Russia

Ms Cooper imposed sanctions on 70 ships in Russia's "shadow fleet" that transport Russian oil, while 30 entities and individuals supporting key equipment such as electronics, chemicals, and explosives used to manufacture missiles and other weapons systems were also targeted.

The foreign secretary said: "The UK will not stand idly by as Putin continues his barbaric invasion of Ukraine. His complete disregard for sovereignty has been shown this week when he recklessly sent drones into Nato airspace.

"The security of Nato and Ukraine is crucial to the UK's security - an integral part of the Prime Minister's plan for change.

"International action to increase economic pressure on Russia and to cut off critical cash flows, which he desperately needs to pay for this illegal war, is vital.

"These sanctions form the next stage in the UK's leading efforts to ramp up economic pressure alongside our security support and our work alongside the coalition of the willing for a just and lasting peace in Ukraine."