The US's top diplomat has said that he sees promise in Ukraine's proposal for a partial ceasefire to end the war with Russia, ahead of talks in Saudi Arabia between US and Ukrainian officials later on Tuesday.

"I'm not saying that alone is enough but it's the kind of concession you would need to see in order to end the conflict," US Secretary of State Marco Rubio said on Monday.

Kyiv is expected to propose an aerial and naval truce with Russia during the negotiations in Jeddah.

Russia has previously rejected the idea of a temporary ceasefire, saying it was an attempt to buy time and prevent Ukraine's military collapse.

In a separate development, at least three people have been killed in a "massive" overnight drone attack on Moscow and the capital region, Governor Andrei Vorobyev said. Seven apartments in a residential building were damaged.

Moscow Mayor Sergei Sobyanin said 74 drones heading toward the city were shot down. The roof of one building was damaged by drone wreckage, he added.

The attack forced the suspension of one district train network, and flight restrictions at Moscow's airports.

Ukrainian President Volodymyr Zelensky landed in Saudi Arabia on Monday to meet Crown Prince Mohammed bin Salman, although he is not expected to play any formal role in the talks with the US.

In his video address late on Monday, Zelensky said he was hoping for a "practical result" at the talks, adding that the Ukrainian position would be "absolutely constructive".

The Ukrainian team will be represented by Zelensky's head of office Andriy Yermak, the country's national security adviser and several foreign and defence ministers.

Rubio will represent the US delegation alongside National Security Adviser Mike Waltz and US Middle East envoy Steve Witkoff.

Before arriving in Jeddah on Monday, Rubio said that it was important to "establish clearly Ukraine's intentions" for a peace deal and that the country would "have to be prepared to do difficult things like the Russians are going to have to do difficult things to end this".

"I'm not going to set any conditions on what they have to or need to do," he added. "We want to listen to see how far they're willing to go, and compare that to what the Russians want, and then see how far apart we truly are."

He said that both sides needed to realise that "there's no military solution" to the conflict and it can only be resolved through "diplomatic means".

Meanwhile, Witkoff is planning to meet Russian President Vladimir Putin in Moscow later this week, Bloomberg and Axios news websites report, citing unnamed sources.

The Kremlin has not publicly commented on the reported visit.

The talks in Jeddah come as US President Donald Trump steps up pressure on Zelensky to agree to a ceasefire with Moscow, without any promises of US security guarantees.

The talks mark the first official meeting since Zelensky's visit to the White House descended into acrimony last month.

Following the heated Oval Office encounter, the US paused military aid and intelligence sharing for Kyiv in an apparent bid to get Zelensky to the negotiating table.

Rubio said that he hoped the pause in aid could be "resolved" but that the negotiations on Tuesday "would be key to that".

The suspension "came about because we felt that they [Ukraine] were not committed to any sort of peace process", he said, and "if that changes, obviously our posture can change".

"The president is going to use whatever tools he has at his disposal to try to get both sides to that table so this war will end," he added.

Earlier on Monday, Trump special envoy Steve Witkoff said he expected "substantial progress" during the negotiations.

Asked whether he thought Zelensky would return to the US to sign a minerals deal later in the week, he told Fox News: "I am really hopeful. All the signs are very, very positive."

Zelensky has previously said he is willing to sign a minerals deal with the US, which would establish a joint fund from the sale of Ukrainian minerals.

Witkoff said that among the issues to be discussed in Saudi Arabia were security protocols for the Ukrainians and territorial issues.

He said the US administration had never shut off intelligence sharing for anything defensive that Ukraine needed, while on Sunday, Trump told Fox News that he had "just about" lifted the intelligence sharing pause on Ukraine.

Sir Keir Starmer also spoke to Trump ahead of the talks, Downing Street said.

The UK prime minister told Trump that "he hoped there would be a positive outcome to the talks that would enable US aid and intelligence-sharing to be restarted," a spokeswoman said.

Russia launched a full-scale invasion of Ukraine in February 2022 and currently holds around a fifth of Ukraine's territory, including Crimea, which it annexed in 2014.