CNBC Daily Open: A thousand drones and one strained U.S.-Ukraine alliance

Volodymyr Zelenskyy is fighting a war of attrition against Russia, and an increasingly difficult war of persuasion in Washington.

Even as Kyiv launches a massive drone strike against the Russian city of St Petersburg and tries to hold back Russian forces on the ground, Zelenskyy is fighting on the diplomatic front to keep Washington in his country's corner.

Over the weekend, Trump defended his decision to lift sanctions on Russian diesel export, as well as suspending new duties on Russian goods and major Russian energy buyers.

The move had attracted bipartisan criticism that he was favoring Russian President Vladimir Putin's interests over those of Ukraine.

Zelenskyy has described the decision as "wrong," and said in an NBC interview that should the U.S. side with Russia in the war, Ukraine will not prevail.

He also said that Washington was restricting Kyiv's Starlink and Starshield networks, hindering the country's ability to respond to Russian assaults.

U.S. Treasury Secretary Scott Bessent then warned the Ukrainian president to "be careful" in public statements about U.S. support for Ukraine.

"President [Donald] Trump and Secretary [Marco] Rubio have categorically said that no one under the Trump administration did that, and I think it is very reckless for President Zelenskyy to make such a charge," Bessent said on "Meet the Press."

"President Zelenskyy should be very careful about making statements like this that aren't true," he added.

When he was asked whether Trump is still an ally of Ukraine, Zelenskyy said: "I hope so."

The U.S. President has also blamed Ukraine's strikes on Russian energy facilities for rising diesel prices, and accused Zelenskyy for not wanting to end the war.

However, a so called "energy ceasefire" last week saw Russia continue to hit Ukrainian energy infrastructure while Kyiv said it paused strikes for three days.

Oil prices have dipped slightly, but are still elevated, with international benchmark Brent at about $107.82 and U.S. West Texas Intermediate at $100.65 in early Asia trade.