Russian President Vladimir Putin received U.S. envoys Steve Witkoff and Jared Kushner at the Kremlin on Saturday for talks aimed at reviving a stalled effort to end the Russia-Ukraine war.

The visit comes amid escalating aerial attacks by both sides, although Putin and Ukrainian President Volodymyr Zelenskyy agreed to pause strikes on each other's capitals while the talks take place. Washington's push to end the fighting has lost momentum over the past six months as U.S. attention has been consumed by the Iran war. The last known Moscow visit by Witkoff and Kushner — the latter is U.S. President Donald Trump's son-in-law — was in January, when they also met Putin at the Kremlin.

The meeting carries added weight because the war is now in its fifth year, making it the largest conflict in Europe since World War II and one that has reshaped energy markets, defense spending, and security policy across the continent. Trump, who took office promising to end the war quickly, has repeatedly expressed frustration with the pace of negotiations on both sides.

Ukrainian officials said both envoys will travel on Sunday to Kyiv, Ukraine's capital, for the first time in the peace process. The planned trip — the envoys' first to Kyiv since the talks began — follows months in which negotiations have largely been confined to meetings in Moscow, Gulf states, and other venues, a format Ukrainian officials have criticized.

At the start of the Moscow meeting, Putin asked Kushner and Witkoff to convey his warm wishes and gratitude to Trump, and described the situation in Ukraine as "not simple." Russian forces launched an all-out invasion of Ukraine on Feb. 24, 2022.

"(Russian President Vladimir) Putin has ordered that no strikes be carried out against Kyiv for three days, starting at midnight today," presidential spokesperson Dmitry Peskov told Russia's Tass news agency.

Zelenskyy said Ukraine was prepared to halt strikes on Moscow until Monday, adding that he spoke with the U.S. delegation Saturday afternoon after their arrival in Moscow. "From now through the end of Saturday, as well as on Sunday and Monday, Ukraine is ready to refrain from strikes on Moscow, and we expect the Russians to do the same regarding Kyiv," he said.

Tass reported that the envoys were met at the Moscow airport by Russian envoy Kirill Dmitriev, who shared photos of himself greeting the U.S. delegation as they disembarked, with the caption: "Welcome to Moscow Peacemakers."

With peace efforts stalled, Russia has stepped up attacks on Kyiv and other cities with relentless bombardments extending into daylight hours, exploiting Ukraine's shortage of air defense systems. On Friday, a Russian drone struck one of Kyiv's most important government buildings — the headquarters of Ukraine's Security Service, known as the SBU, one of the agencies carrying out deep-strike operations inside Russia.

Ukraine's long-range strikes, for their part, have hit Russian military facilities, oil refineries, and e-commerce hubs, seeking to undermine the Kremlin's war effort and economy and make ordinary citizens feel the consequences of the war.

The air war has intensified as troops have struggled to make progress along the 1,250-kilometer (775-mile) front line. Russia has recently deployed fast-flying, jet-powered drones, which are harder to intercept than the slower propeller-driven Shahed-type models, and the recurring wail of air-raid sirens has become part of daily life in Kyiv.

In a social media post on Saturday, Zelenskyy said Russia had carried out overnight strikes on Kyiv's airports and Boryspil international airport, linking the attack to the planned U.S. visit. "Clearly, these Russian strikes on the airports are a reaction to the discussions and preparations for the possibility of the U.S. side using an aircraft to travel to Ukraine," he said.

"We have taken note of this Russian move, and next week we will adjust our operation accordingly regarding Russian airspace, which has become dangerous because of our drones and missiles in the sky. Of course, there are and will be no threats to diplomacy from our side," he added.

On the ground, Russian attacks killed five people and wounded five others at an industrial facility in Ukraine's southern Dnipropetrovsk region, according to local military administration head Oleksandr Hanzha, who said those killed were employees at the site. "A locksmith, an electrician, a plumber and a machinist. People of peaceful professions. They were simply working their shift. They were doing their job when enemy missiles cut off their lives," he said. In a separate attack on the region's Nikopol district, a 62-year-old man was wounded and several homes and an apartment building were damaged, Hanzha said.

In a statement on Saturday, Russia's Ministry of Defense said it had struck two metallurgical plants in the region, describing them as "major suppliers of metal products for Ukraine's military production."

Two more people were wounded in an overnight Russian attack on the Kyiv region, said Tymur Tkachenko, head of the regional military administration. In the Boryspil district, a fire sparked by a strike partially destroyed a nine-story residential building.

Russian forces also repeatedly struck a shopping center in the southern Mykolaiv region with drones overnight, damaging retail premises and sparking fires, Ukraine's state emergency services said. A 72-year-old man and a 17-year-old girl were wounded. Emergency crews responding to the attack were repeatedly forced to withdraw to safety because of the threat of further strikes, returning whenever conditions allowed, the emergency services said.

Ukraine's air force said Russia launched ballistic missiles from its Rostov and Voronezh regions and deployed 167 attack drones overnight, including Shahed-type aircraft — around half of them jet-powered — as well as Geran and decoy drones. Ukrainian air defenses shot down or suppressed 128 of the drones, according to the air force.

Elsewhere, Ukrainian attacks wounded three people, including a 14-year-old girl, in Russia's border region of Belgorod, local officials said. Russia's Defense Ministry said its forces shot down 53 Ukrainian drones overnight.

This story was originally featured on Fortune.com.