WASHINGTON () President Donald Trump is “disappointed but not done” with Russian President Vladimir Putin, following an announcement of new military support for Ukraine and a plan to target buyers of Russian oil with severe tariffs.

Speaking to the BBC hours after the announcement, Trump expressed frustration with Putin’s resistance to U.S.-led peace efforts, and when pressed on whether he trusts the Russian leader, he replied: “I trust almost nobody.”

Russia has 50 days to negotiate a ceasefire with Ukraine. If not, countries that continue to import Russian energy could face secondary tariffs of up to 100%, Trump said.

Former Russian President Dmitry Medvedev called Trump’s move a “theatrical ultimatum,” posting on social media: “The world shuddered, expecting the consequences. Belligerent Europe was disappointed. Russia didn’t care.”

While the Kremlin has not directly responded to Trump’s remarks, a senior Russian official involved in negotiations with the United States described the move as a “doomed-to-fail attempt at pressure.”

Russia has continued to receive weapons from its trading partners, helping it bypass existing sanctions.

‘Severe’ tariff threat on Russia looms

Trump has said he hopes the tariff threat can push a deal to end Russia’s three-year war in Ukraine.

“We thought we had four deals with Putin,” Trump said Monday. “We get off the phone after a nice conversation, and then he sends missiles into buildings. I said, ‘What was that all about?’”

June marked the highest number of civilian casualties of the war, according to the U.N. Human Rights Monitoring Mission in Ukraine.

Seated alongside NATO Secretary General Mark Rutte in the Oval Office on Monday, Trump also announced new weapons for Ukraine and threatened secondary tariffs of 100% on buyers of Russian exports, of which crude oil makes up a significant portion.

Trump’s tariff threat is aimed at countries funding Russia’s war through oil and gas purchases, which remain Moscow’s key revenue stream. The proposed 100% tariffs would drastically increase economic pressure on those buyers.

US tariffs, weapons support gains bipartisan backing

Trump’s plan received bipartisan support on Capitol Hill. 

Senators Lindsey Graham, R-S.C., and Richard Blumenthal, D-Conn., said they’d push a bill to impose 500% tariffs against any country importing Russian oil and gas legislation that already gathered more than 80 co-sponsors.

Trump signaled the bill may not be needed if Russia agrees to a ceasefire.

Zelenskyy thanks Trump, NATO for renewed support

Ukrainian President Volodymyr Zelenskyy thanked Trump and NATO for the new military aid.

On Monday, he spoke with Trump by phone, calling it a “good conversation” and expressing gratitude for U.S. support.

“Thank you for the willingness to support Ukraine and to continue working together to stop the killings and establish a lasting and just peace,” Zelenskyy wrote.

Zelenskyy also met in Kyiv with Trump’s special envoy, retired Lt. Gen. Keith Kellogg, amid growing speculation that the Trump administration could shift its stance on the war.

With renewed aid, Ukraine is expected to receive more defense missiles to help repel intensifying Russian airstrikes. Some NATO members are also preparing to transfer Patriot missile systems to bolster Ukraine’s defenses.

The Associated Press and Reuters contributed to this report.