Washington. US President Donald Trump and Russian President Vladimir Putin agreed during a lengthy call Tuesday to an immediate pause in strikes against energy infrastructure in the Ukraine war, but the Russian leader stopped short of backing a broader 30-day pause in fighting that the US administration is pressing for.

The White House described it as the first step in a “movement to peace” that it hopes will include a maritime ceasefire in the Black Sea and eventually a full and lasting end to the fighting.

Putin during the call reiterated his demand for an end to foreign military and intelligence assistance to Ukraine, according to the Kremlin.

And there was no indication that he has backed away from his conditions for a prospective peace deal, which are fiercely opposed by Kyiv. Russia wants Ukraine to pull back its troops from the four regions that Moscow has annexed but never fully captured, renounce any prospect of joining the NATO military alliance and sharply cut its army.

Shortly after the call ended, air raid alerts sounded in Kyiv, followed by explosions in the city. Local officials urged people to seek shelter.

Ukrainian President Volodymyr Zelensky told reporters that Ukraine is open to any proposals that lead to a sustainable and just peace, but stressed the need for full transparency in discussions.

Zelensky said he was seeking more details on what Putin and Trump agreed on, but rejected Putin’s demand for halting military aid and intelligence sharing to Ukraine, warning that such a move would weaken Ukraine.

“We need to understand what the conversation is about," Zelensky said. “What are the details? And hopefully, we will be fully informed, and our partners will discuss everything with us.”

He added: “There are two sides in this war -- Russia and Ukraine. Trying to negotiate without Ukraine, in my view, will not be productive."

Ukrainian officials earlier this month proposed a ceasefire covering the Black Sea and long-range missile strikes and the release of prisoners.

Trump immediately cheered Tuesday's development as a major step toward his ultimate goal of ending the biggest land war in Europe since World War II.

“We agreed to an immediate Ceasefire on all Energy and Infrastructure, with an understanding that we will be working quickly to have a Complete Ceasefire and, ultimately, an END to this very horrible War between Russia and Ukraine,” Trump said on social media.

Putin also told Trump that Russia and Ukraine are set to exchange 175 prisoners of war each on Wednesday, and Russia will also hand over to Ukraine 23 badly wounded soldiers, the Kremlin said.

The limited pause comes as Trump still hopes to get Russia to sign off on his 30-day ceasefire proposal aimed at ending the Russian invasion of Ukraine.

Ukrainian officials last week agreed to the 30-day ceasefire proposal during talks in Saudi Arabia led by Secretary of State Marco Rubio. White House special envoy Steve Witkoff then met with Putin in Moscow to discuss the proposal.

Zelensky, however, remains skeptical that Putin is ready for peace as Russian forces continue to pound Ukraine.

“This is not a game where only Putin dictates the rules,” Zelensky said, making clear he remains doubtful that Putin was serious about wanting peace.

The Trump-Putin engagement is just the latest turn in dramatically shifting US-Russia relations as Trump made quickly ending the conflict a top priority -- even at the expense of straining ties with longtime American allies who want Putin to pay a price for the invasion.

Trump has at moments boasted of his relationship with Putin and blamed Ukraine for Russia’s unprovoked invasion, all while accusing Zelensky of unnecessarily prolonging the war.

Trump has said Washington and Moscow have already begun discussing “dividing up certain assets” between Ukraine and Russia as part of a deal to end the conflict.

He said before the call that control of land and power plants would be part of the conversation, which came on the anniversary of Russia annexing Ukraine's Crimean Peninsula 11 years ago. That bold land grab by Russia set the stage for Russia to invade its neighbor in 2022.

But neither the White House nor Kremlin made any mention of land or power plants in their post-call statements.

Witkoff on Sunday suggested that US and Russian officials have discussed the fate of the Zaporizhzhia nuclear power plant -- Europe's largest -- in southern Ukraine. Russian troops seized the plant early in the war and it has been caught in the crossfire, fueling fears of a potential nuclear catastrophe.

The plant is a significant asset, producing nearly a quarter of Ukraine’s electricity in the year before the war.

After a disastrous Feb. 28 White House meeting with Zelensky, Trump temporarily cut off some military intelligence-sharing and aid to Ukraine. It was restored after the Ukrainians last week signed off on the Trump administration's 30-day ceasefire proposal.

In his dealings with Zelensky and Putin, Trump has frequently focused on who has the leverage. Putin has “the cards” and Zelenskyy does not, Trump has said repeatedly.

Trump, who has long shown admiration for Putin, has also made clear he'd like to see the US-Russia relationship return to a more normal footing.

The president during his recent contentious meeting with Zelensky grumbled that “Putin went through a hell of a lot with me," a reference to the federal investigation into Russian interference in the 2016 presidential election in which he beat Democrat Hillary Clinton.

Trump on Tuesday again underscored his view that Ukraine is not in a strong negotiating position. He said Russian forces have surrounded Ukrainian troops in Russia's Kursk region -- amplifying an assertion made by Russian officials that's been disputed by Zelensky.

“They are nicely encircled, and that’s not good,” said Trump, according to excerpts of an interview on Fox News Channel's "Ingraham Angle." “And we want to get it over with.”

Ukraine’s army stunned Russia in August last year by attacking across the border and taking control of an estimated 1,300 square kilometers (500 square miles) of land. But Ukraine’s forces are now in retreat and it has all but lost a valuable bargaining chip, as momentum builds for a ceasefire with Russia.