President Donald Trump said Saturday he is “ready to do major Sanctions on Russia” once all NATO countries have started “to do the same thing” and pause their purchases of oil from Moscow.

He also urged NATO countries to impose “50% to 100% TARIFFS ON CHINA,” which he said should be withdrawn after the Russia-Ukraine war has concluded.

“China has a strong control, and even grip, over Russia, and these powerful Tariffs will break that grip,” Trump wrote in a Truth Social post, which he said was the text of a letter sent to all NATO nations and “the world.”

Trump has repeatedly threatened to impose sanctions on Russia over its invasion of Ukraine, but has so far held off from doing so.

Earlier this month, the president said he was prepared to move towards a second phase of sanctioning Russia, but has not yet imposed the levies.

Part of Trump’s reluctance to impose the strict economic punishments may be in part because he hopes he can broker a peace deal between Ukraine and Russia, analysts previously told CNBC.

“The second reason … is there is a sense that if Russia is defeated … then it has no choice but to go even further all-in with China, and that potentially then would strengthen China’s position,” Chris Weafer, the chief executive of Moscow-based Macro-Advisory, told CNBC earlier this month.

Trump’s Saturday post underscores that he is shifting his focus to NATO nations to put pressure on Russia to end its war.

“As you know, NATO’S commitment to WIN has been far less than 100%, and the purchase of Russian Oil, by some, has been shocking!” Trump wrote in the post.

“It greatly weakens your negotiating position, and bargaining power, over Russia,” he continued.

Hungary and Slovakia have continued to buy Russian fossil fuels, drawing criticism from Trump officials.

“We want to displace all Russian gas. President Trump, America, and all the nations of the EU, we want to end the Russian-Ukraine war,” U.S. Secretary of Energy Chris Wright said Friday.