MOSCOW/KYIV/BUDAPEST - A meeting between Russian President Vladimir Putin and Ukrainian President Volodymyr Zelensky is not being planned, Russian Foreign Minister Sergei Lavrov said Friday as heavy fighting between Russia and Ukraine dragged on.

"Putin is ready to meet with Zelensky when the agenda would be ready for a summit, and this agenda is not ready at all," Lavrov told the US news outlet NBC.

His comments came a week after US President Donald Trump met with Putin in the US state of Alaska for talks aimed at ending the three-year conflict in Ukraine. The US president also met with Zelensky and European leaders on Monday.

The latest discussions of a potential Putin-Zelensky meeting surfaced after Trump said he called Putin and started working on a bilateral meeting between Putin and Zelensky -- and possibly a trilateral one including himself -- following his talks on Monday.

Commenting on the potential meetings, Trump told reporters Friday: "We're going to see if Putin and Zelensky will be working together. You know, that's like oil and vinegar a little bit."

"They don't get along too well ... but we'll see, and then we'll see whether or not I would have to be there. I'd rather not. I'd rather have them have a meeting and see how they can do," he said.

Lavrov told NBC that Russia has agreed to show flexibility on several issues raised by Trump during his meeting with Putin.

The foreign minister previously said that Russia does not reject any formats, either bilateral or trilateral, on resolving the conflict in Ukraine, but noted that any contacts over Ukraine involving top officials need to be prepared "extremely carefully."

Zelensky on Friday said Russia is "doing everything" to prevent his meeting with Putin from taking place.

"The meeting is one of the components of how to end the war. And since they don't want to end it, they will look for space to (avoid it)," he added.

On the frontline, both Russia and Ukraine have intensified attacks on each other's energy infrastructures over the past week.

The Russian Defense Ministry said Friday that over the past week, Russian troops captured nine settlements and launched six group strikes targeting the Ukrainian military-industrial complex and energy facilities, an oil refinery, and storage sites of Ukrainian missiles, fuel, rocket-artillery weapons, and long-range drones.

During the period, Russian air defense systems shot down 25 guided aerial bombs, 11 rocket projectiles from the US-made HIMARS multiple launch rocket system, as well as 1,500 drones, it said.

Zelensky said Thursday that Russia launched one of the largest strikes against Ukraine overnight involving over 570 drones and 40 missiles. A US factory in western Ukraine was targeted, he added.

The commander of Ukraine's Unmanned Systems Forces, Robert Brovdi, announced on Friday an attack on the Unecha pumping station in Russia's Bryansk region.

The station is a crucial part of the Druzhba oil pipeline, which supplies oil to Hungary and Slovakia. Hungarian Prime Minister Viktor Orban said Friday the pipeline was subjected to repeated Ukrainian attacks over the past weeks.

Crude oil deliveries to Hungary have been suspended again following an overnight attack on the pipeline, Hungarian authorities said.

In a post on Facebook, Hungarian Minister of Foreign Affairs and Trade Peter Szijjarto described the incident as "another attack against our country's energy security".

This was the third such incident in a short period, the minister said, adding that Hungary would continue to support peace efforts with all its strength while defending its national interests.

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The Druzhba pipeline was previously struck on Monday, leading to a temporary halt in supplies. Hungarian oil and gas group MOL said fuel production remained uninterrupted and consumers saw no shortages after that attack, thanks to reserves and an alternative southern route through the Adriatic pipeline.

Szijjarto, together with Slovak Foreign Minister Juraj Blanar, has sent a joint letter to senior European Union (EU) officials, urging the European Commission to take immediate action following the attack.

US-Russia possible cooperation on LNG projects

Separately, Putin said Russia and the US are discussing the possibility of cooperating in liquefied natural gas (LNG), not only in the Russian Arctic zone but also in Alaska.

Speaking at a meeting with nuclear industry workers and scientists in Sarov, Nizhny Novgorod region, Putin noted that several Russian companies, including major LNG producer Novatek, are already cooperating with partners from Europe and Asia.

"We are also discussing with American partners the possibility of working together in this area, and not only in our Arctic zone, but also in Alaska," Putin said, quoted by TASS news agency.

Putin noted that Russia possesses unique LNG technologies, which have attracted the interest of its partners, including those from the US.

Zelensky, NATO chief meet

On Friday, Zelensky said he discussed security guarantees for Ukraine during a meeting with North Atlantic Treaty Organization (NATO) Secretary-General Mark Rutte in Kyiv.

Following the talks, Zelensky said that Ukraine aims to secure "Article 5-like" guarantees, similar to Article 5 of the North Atlantic Treaty.

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"The outcome we must achieve: a crystal-clear architecture of which countries assist us on the ground, which are responsible for the security of our skies, which guarantee security at sea and support Ukraine," Zelensky said in a statement on his official website.

He added that guarantees should also include financing of the Ukrainian military from partner nations.

According to Zelensky, negotiations between Ukraine, Europe and the United States on the specific content of the security guarantees are ongoing.

Zelensky and Rutte also discussed weapons deliveries to Ukraine coordinated under the Prioritized Ukraine Requirements List, proposed by NATO and the United States, as well as joint efforts aimed at ending the Russia-Ukraine conflict.

65 Ukrainians return home

Separately, 65 Ukrainians, deported from Russia and stranded at the Russian-Georgian border, have returned home, Ukrainian Foreign Minister Andrii Sybiha said Friday.

Among them were 10 women and eight seriously ill individuals, Sybiha said in a post on Facebook.

All deportees had been stuck at the buffer zone of the Dariali checkpoint on the border, according to the post.

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Over the past several months, Ukraine has received 109 deported citizens from the checkpoint, Sybiha said.