BASKING RIDGE, N.J. (AP) — President Donald Trump said Saturday he believes the Russia-Ukraine war would end if all NATO countries stopped buying oil from Russia and placed tariffs on China of 50% to 100% for its purchases of Russian petroleum.

Trump posted on his social media site that NATO’S commitment to winning the war “has been far less than 100%” and the purchase of Russian oil by some members of the alliance is “shocking.” As if speaking with NATO members, he said: “It greatly weakens your negotiating position, and bargaining power, over Russia.”

Since 2023, NATO member Turkey has been the third largest buyer of Russian oil, after China and India. according to the Centre for Research on Energy and Clean Air. Other members of the 32-state alliance involved in purchasing Russian oil include Hungary and Slovakia. It’s unclear whether Trump would want to directly confront Turkish President Recep Tayyip Erdogan or Hungarian Prime Minister Viktor Orbán. That leaves uncertain whether the threats might actually lead to new tariffs or a ban on Russian oil purchases.

Trump’s post arrives after the Wednesday flight of multiple Russian drones into Poland, an escalatory move by Russia as it was entering the airspace of a NATO ally. Poland shot down the drones, yet Trump played down the severity of the incursion and Russia’s motives by saying it “could have been a mistake.”

While Trump as a candidate promised to end the war quickly, he has yet to hit the pressure points needed to end the violence and has at times been seen as reluctant to confront Russian President Vladimir Putin. Congress is currently trying to get the U.S. president to back a bill toughening sanctions, after Trump last month hosted Putin in Alaska for talks that failed to deliver on progress toward peace.

The U.S. and its allies are seeking to show a firmer degree of resolve against Russia. At an emergency U.N. Security Council meeting Friday, acting U.S. Ambassador Dorothy Shea said America “will defend every inch of NATO territory” and that the drones entering Poland “intentionally or otherwise show immense disrespect for good-faith U.S. efforts to bring an end to this conflict.”

Britain on Friday also took steps to penalize the trading of Russian oil, including a ban on 70 vessels allegedly used in its transportation. The United Kingdom also sanctioned 30 individuals and companies, included businesses based in China and Turkey, that have supplied Russia with electronics, chemicals, explosives and other weapons components.

Trump in his post Saturday said a NATO ban on Russian oil plus tariffs on China would “also be of great help in ENDING this deadly, but RIDICULOUS, WAR.”

The president said that NATO members should put the 50% to 100% tariffs on China and withdraw them if the war that launched with Russia’s 2022 invasion of Ukraine ends.

“China has a strong control, and even grip, over Russia,” he posted, and powerful tariffs “will break that grip.”

The U.S. president has already imposed a 25% import tax on goods from India, specifically for its buying of Russian energy products. He has placed in total a 50% tariff on India, though Trump has indicated that negotiations with Indian Prime Minister Narendra Modi could help settle differences.

The prospect of further import tax hikes on China and its retaliation could carry collateral damage for the U.S. and European economies.

Earlier this year, Trump hit Chinese goods with new tariffs totaling 145%, prompting China to respond with 125% import taxes on American goods. Taxes at that level were essentially a blockade on commerce between the world’s two largest economies, causing worries about global growth that led to negotiations that ratcheted down the tariffs being levied by both nations.

So that trade talks could proceed, America lowered its tariffs against China to a still-high 30%, while China took its rate to 10%.

In his post, the Republican president said responsibility for the war fell on his predecessor, Democrat Joe Biden, and Ukrainian President Volodymyr Zelenskyy. He did not include in that list Putin, who launched the invasion.

Trump’s post builds on a call Friday with finance ministers in the Group of Seven, a forum of industrialized democracies. During the call, U.S. Trade Representative Jamieson Greer and Treasury Secretary Scott Bessent called on their counterparts to have a “unified front” to cut off “the revenues funding Putin’s war machine,” according to Greer’s office.