LONDON — National Security Adviser Mike Waltz said Thursday that officials in Kyiv “need to tone it down” after a fierce back and forth between President Donald Trump and Ukrainian President Volodymyr Zelenskyy related to a potential deal to end Russia’s three-year-old invasion of its neighbor.

U.S.-Russia talks began this week in Saudi Arabia without Ukrainian participation, Kyiv’s exclusion prompting condemnation in Ukraine and across Europe as well as a vow from Zelenskyy that his country would not sign any deal agreed over its head. Zelenskyy also pushed back on a proposed deal that would give the U.S. access to hundreds of billions of dollars worth of minerals.

Responding to the discord, Waltz told Fox News that the Ukrainians “need to tone it down and take a hard look and sign that deal,” referring to the proposed minerals agreement.

“There’s obviously a lot of frustration here,” Waltz said after Wednesday’s war of words.

Seeking to explain the strong remarks from Trump and Vice President JD Vance, Waltz said, “We presented the Ukrainians really an incredible and historic opportunity to have the United States of America co-invest with Ukraine, invest in its economy, invest in its natural resources and really become a partner in Ukraine’s future in a way that’s sustainable, but also would be — I think — the best security guarantee they could ever hope for, much more than another pallet of ammunition.”

Trump on Wednesday attacked European allies and the Ukrainian leadership for having failed to end Russia’s war. The president went on to call Zelenskyy a “dictator without elections,” claiming — without providing evidence — that his Ukrainian counterpart’s public approval rating was as low as 4%.

Trump also wrote on Truth Social that Zelenskyy “better move fast or he is not going to have a country left.”

Zelenskyy, meanwhile, suggested Trump is in a “disinformation space,” attributing at least some of the U.S. leader’s criticism to Russian disinformation campaigns.

Vance then warned that Zelenskyy’s approach to dealing with the Trump White House was “atrocious.”

In Moscow, meanwhile, Kremlin spokesperson Dmitry Peskov told reporters Thursday that Ukrainian officials had made “unacceptable and impermissible” remarks about foreign leaders “in recent months.”

“Rhetoric used by Zelenskyy and numerous other representatives of the Kyiv regime in general leaves much to be desired,” Putin’s spokesperson said.

The diplomatic spat was set against the backdrop of continued Russian strikes across Ukraine. On Thursday, Ukraine’s air force said Russia launched 14 missiles and 161 drones into the country in a massive overnight bombardment.

Ukraine’s air force said it shot down 80 of the drones launched in the latest Russian barrage, with another 78 lost in flight without causing any damage. The 14 missiles targeted energy infrastructure, the air force said, adding it would not reveal how many were intercepted.

Ukrainian Energy Minister German Galushchenko wrote on Facebook that Russia conducted a “massive” missile and drone attack on “gas infrastructure.”

The aim of the “criminal attacks” was to “stop the production of gas, which is necessary to provide citizens’ household needs and centralized heating,” he said.

“While Russia continues to blatantly lie about not attacking civilian critical infrastructure, we are witnessing multiple missiles targeting Ukrainian gas mining facilities at once,” Galushchenko wrote.

“Such actions of the enemy prove only once again that Russia is trying to hurt ordinary Ukrainians, plunged into the cold in the middle of winter,” he added. “This is outright terrorism.”

Russia’s Defense Ministry, meanwhile, said its strike targeted “gas and energy infrastructure facilities that ensure the operation of the military-industrial complex of Ukraine.”

“The strike’s objective has been achieved,” the ministry said. “All facilities have been hit.”

Russia’s long-range strikes into Ukraine have not eased despite the opening of talks aimed at ending Moscow’s three-year-old full-scale invasion of Ukraine.

Russia’s latest salvo came with Trump’s Ukraine-Russia envoy Keith Kellogg in Kyiv to meet with Ukrainian leaders. Items of discussion are expected to include the proposed deal with the U.S. for access to the country’s mineral resources and the larger possible peace deal with Moscow.

On Thursday, Zelenskyy marked the anniversary of the culmination of Ukraine’s 2014 Maidan Revolution — in which pro-Western protesters overthrew Moscow-aligned President Viktor Yanukovych.

“It was in these days of 2014 that Russia chose war — it began the first steps towards the occupation of Crimea,” Zelenskyy wrote on Telegram. “While people were being killed in Kyiv, and people were defending their freedom, Putin decided to strike another blow.”

“Since then, the world has been living in a new reality, when Russia is trying to deceive everyone,” the president wrote. “And it is very important not to give in, to be together. It is very important to support those who defend freedom.”

Ukraine is continuing its own long-range campaign against Russian military and industrial infrastructure, especially targets linked to the country’s lucrative fossil fuel industry. Ukrainian security services have referred to the campaign as “drone sanctions.”

Russia’s Defense Ministry said on Thursday that its forces shot down 13 Ukrainian drones over the previous 24 hours.

ABC News’ Nataliia Popova, Oleksiy Pshemyskiy, Fidel Pavlenko, Kelsey Walsh and Joe Simonetti contributed to this report.