President Donald Trump called on all NATO members to stop buying Russian oil and threatened tariffs of 50% to 100% on China for purchases of Russian petroleum, saying such measures would help end the war in Ukraine.

Trump posted the remarks Saturday on his social media site, saying NATO’s commitment to winning the war "has been far less than 100%" and calling the purchase of Russian oil by some alliance members "shocking." He said a unified ban would "greatly weaken your negotiating position, and bargaining power, over Russia."

Trump said the tariffs on China should be set at 50% to 100% and withdrawn only if the war that began with Russia’s 2022 invasion of Ukraine ends. He asserted that "China has a strong control, and even grip, over Russia," and called high tariffs a way to "break that grip." The president also said responsibility for the war lay with his predecessor, Democrat Joe Biden, and Ukrainian President Volodymyr Zelenskyy; his post did not name Russian President Vladimir Putin.

Data from the Centre for Research on Energy and Clean Air cited by analysts shows Turkey was the third-largest buyer of Russian oil in 2023, after China and India. Several NATO members, including Hungary and Slovakia, have also purchased Russian petroleum. NATO comprises 32 member states.

Trump’s post came days after multiple Russian drones entered Polish airspace on Wednesday in an escalation that raised alarm among NATO members. Polish forces shot down the drones. Trump said the incursion "could have been a mistake," a comment that drew attention as U.S. and allied officials sought to portray the event as a serious breach. At an emergency U.N. Security Council meeting Friday, acting U.S. Ambassador Dorothy Shea said the United States "will defend every inch of NATO territory" and that the drones, "intentionally or otherwise," showed "immense disrespect for good-faith U.S. efforts to bring an end to this conflict."

The White House and Congress have been at odds over how to tighten pressure on Moscow. Lawmakers are pursuing a bill to toughen sanctions, and officials have emphasized the need to cut off revenues that sustain Russia’s military campaign. Trump hosted Putin in Alaska last month for talks that produced no public progress toward a peace agreement, and some critics have said the president has been reluctant at times to confront the Russian leader.

British officials on Friday announced measures to further restrict Russia’s ability to trade oil, including a ban on 70 vessels alleged to have been used to transport Russian crude. The United Kingdom also sanctioned 30 individuals and companies, including businesses in China and Turkey, that British authorities said supplied Russia with electronics, chemicals, explosives and other components used in weapons systems.

Trump noted that the United States already has imposed a 25% import tax on goods from India over that country’s purchases of Russian energy products. He said the proposed NATO oil ban and tariffs on China "would also be of great help in ENDING this deadly, but RIDICULOUS, WAR."

The president’s tweet built on a Friday conference call with finance ministers from the Group of Seven. U.S. Trade Representative Jamieson Greer and Treasury Secretary Scott Bessent urged their counterparts to maintain a "unified front" to cut off what Greer’s office called the revenues "funding Putin's war machine."

Administration officials and allies face competing pressures as they weigh measures that could reduce Russian revenues while avoiding widespread global economic disruption. Some NATO members have been reluctant to sever energy ties completely because of domestic needs and differing diplomatic priorities. Trump’s public call for tariffs and an alliance-wide oil ban frames those discussions in sharply economic terms and signals a push for more aggressive, trade-based tools to try to hasten an end to the conflict in Ukraine.

Congressional action on new sanctions and further allied steps appear likely to remain a central focus in coming weeks as U.S. and allied policymakers respond to the drone incursions and other escalatory moves tied to the war.