WILLIAM BRANGHAM: Ukraine's president today concluded a three-day tour of Europe and received new military and political support.

Nick Schifrin reports.

NICK SCHIFRIN: In a 16th century English manor 1,500 miles from Kyiv, British Prime Minister Rishi Sunak today gave Ukraine's president Volodymyr Zelenskyy more military support and a historical blessing.

RISHI SUNAK, British Prime Minister: Winston Churchill made many of his famous speeches in World War II from this room, and, the same way today, your leadership, your country's bravery and fortitude are an inspiration to us all.

NICK SCHIFRIN: The U.K. will now send Ukraine long-range attack drones, in addition to air-launched cruise missiles with a range of 150 miles.

That's almost exactly the same range as an American long-range missile the Biden administration has so far refused to provide.

VOLODYMYR ZELENSKYY, Ukrainian President: Thank you very much for this package that you prepared.

Great.

Huge.

Really what can save the lives for all our people.

NICK SCHIFRIN: Last night, Zelenskyy met French President Emmanuel Macron in Paris, following a weekend audience with the pope, public support from Italy's Prime Minister Giorgia Meloni, whose coalition has close ties with Russia, and an unprecedented military package from German Chancellor Olaf Scholz and a message designed to end doubt about German commitment to Kyiv.

OLAF SCHOLZ, German Chancellor (through translator): We will support Ukraine as long as it is necessary.

JENNIFER CAFARELLA, Institute for the Study of War: Continuing to rally NATO and to foster NATO unity is essential for Ukraine, not only for the current phase of the counteroffensive, but also long term.

NICK SCHIFRIN: Jennifer Cafarella is a national security fellow at the D.C. think tank Institute for the Study of War.

She says British weapons that will expand Ukraine's Western weapons range will allow Kyiv to target Russian supply lines, including in Crimea.

JENNIFER CAFARELLA: They need to be able to apply pressure now through long-range systems that can -- that can degrade and disrupt the Russian capacity to respond to that counteroffensive when it is launched.

And they need to start retaking terrain that the Russians are using for ground resupply.

And the kinds of targets the Ukrainians could choose to go after are threatening the Russian ground supply lines into Crimea.

NICK SCHIFRIN: In private, Zelenskyy has reportedly wanted to go even further.

An intelligence community leak reported by The Washington Post says Zelenskyy advocated for attacking inside Russia and even occupying Russian territory.

He has promised not to do that with Western weapons, a vow he repeated this weekend.

VOLODYMYR ZELENSKYY (through translator): We are concentrated on preparing the counteroffensive to deoccupy only our territories, as recognized by the entire world.

NICK SCHIFRIN: Even ahead of that counteroffensive, Ukraine says it made its first advances in six months in Bakhmut, the war's longest and bloodiest battle.

In another U.S. intelligence community assessment reported in The Washington Post, Yevgeny Prigozhin, the leader of the mercenary Wagner Group, offered Kyiv targeting assistance for Russian positions, in exchange for giving up Bakhmut.

Today, Prigozhin denied it, but, for the first time, he has personally called out Vladimir Putin.

JENNIFER CAFARELLA: Prigozhin is getting increasingly desperate.

And, in his desperation, Prigozhin is crossing new lines.

This sows further dissent within the Russian sphere.

NICK SCHIFRIN: But Ukraine continues to fight an existential war, one that, thanks to this European visit, has more support on the way.

For the "PBS NewsHour," I'm Nick Schifrin.