US President Donald Trump has issued a letter to NATO nations, urging them to stop buying Russian oil and impose major sanctions on Russia to end its war in Ukraine.
He also suggested members of the transatlantic alliance consider slapping tariffs of 50% to 100% on China as a way to help end Russia's war in Ukraine.
"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," he said in a social media post.
"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," he added.
Mr Trump has repeatedly threatened Russia with additional sanctions - including last weekend after the Kremlin unleashed its biggest-ever aerial barrage against Ukraine - as a way to hit at revenue Moscow needs for its grinding war.
But so far he has failed to follow through, frustrating Kyiv.
The president, who met his Russian counterpart Vladimir Putin last month at a summit in Alaska, branded NATO nations' purchase of Russian oil "shocking" and said it weakens their bargaining power over Moscow.
"Anyway, I am ready to 'go' when you are. Just say when?"
Mr Trump also raised the prospect of NATO imposing tariffs on China, which is believed to have boosted strategic cooperation with Moscow and held a high-profile summit with Mr Putin recently in Beijing.
"I believe that (NATO sanctions on Russia), plus NATO, as a group, placing 50% to 100% tariffs on China, to be fully withdrawn after the war with Russia and Ukraine is ended, will also be of great help in ending this deadly, but ridiculous war," Mr Trump said.
"China has a strong control, and even grip, over Russia, and these powerful tariffs will break that grip," he said.
The president has imposed an additional 25% tariff on Indian goods, citing its continued imports of Russian oil, but has not taken similar action against China.
Ukraine hits one of Russia's largest oil refining complexes
Mr Trump's comments came as a Ukrainian drone crashed into one of Russia's largest oil refining complexes, sparking a fire and causing minor damage, a Russian official said.
The complex, which belongs to Russian oil company Bashneft, lies on the outskirts of the central Russian city of Ufa around 1,400km from the front line in Ukraine.
Videos posted on social media appeared to show a drone drifting towards the facility before exploding in a ball of flames, sending a cloud of smoke into the sky.
"Today, Bashneft's facility was subjected to a terrorist attack by aircraft-type drones," the head of Russia's Bashkortostan region, Radiy Khabirov, said on Telegram.
One drone crashed into the plant, while another was shot down, he said.
"There were no casualties or injuries. The production site sustained minor damage, and a fire broke out, which is currently being extinguished," he added.
A source in Ukraine's GUR military intelligence agency claimed responsibility for the attack.
Since Moscow launched its full-scale military offensive in Ukraine in February 2022, Kyiv has responded with attacks on Russian refineries in an attempt to curb the Kremlin's ability to fund the conflict.
A wave of Ukrainian attacks on Russian refineries over the summer hit processing capacity at several key sites and pushed fuel prices up at the pump.
The Kremlin described Bashneft's Ufa refining complex in 2016 as "one of the largest in the country", saying it produced more than 150 types of oil products.
