BRUSSELS, Belgium -- Hailed as a European hero on his arrival in Brussels, Ukraine's President Volodymyr Zelensky urged EU leaders on Thursday to accelerate the promised delivery of modern long-range weapons.

The Ukrainian leader warned that he could not return empty-handed from what was only his second foreign trip since Moscow launched its full-scale invasion just under a year ago.

With a renewed Russian offensive piling pressure on Kyiv's forces in the east, the former actor turned war leader urged his allies to turn what he said were their "positive signals" into "concrete" words.

After Wednesday's visits to London and Paris to lobby Britain, France and Germany for modern fighter jets and long-range missiles, Zelensky flew on to Brussels to address EU leaders and the European parliament.

MEPs treated him to cheers and a standing ovation as he portrayed Ukraine as the country fighting to defend Europe's eastern borders and urged a rapid welcome into the EU fold.

"We are defending against the most anti-European force of the modern world -- we are defending ourselves, we Ukrainians on the battlefield, along with you," Zelensky told MEPs.

After the parliamentary address, Zelensky joined the 27 leaders of the EU member states as the special guest at their regular summit, invited by European Council president to make an opening address.

"I have to thank you personally for your unwavering support of our country and our aspirations, our aspirations to live in a united, free Europe," he told them.

But he also warned that Ukraine needs to receive artillery, munitions, modern tanks, long-range missiles and fighter jets faster than Russia can prepare what he said would be a dangerous new offensive.

He said he saw "positive signals, concerning the respective weapons" from EU leaders and expressed hope those murmurs would become a "concrete voice".

After hours of talks, Zelensky left the summit and had an audience with Belgium's King Philippe.

Kremlin warning

European Council president and summit host Charles Michel insisted that the summit had allowed EU leaders to "make it clear that they are ready to provide more military support".

"The next weeks and the next months will probably be decisive," he said.

Slovak Prime Minister Eduard Heger tweeted that he had heard Zelensky's plea for weapons "including MiG-29s (fighter jets) to protect your sky and people," adding: "I will work on it."

But some EU leaders were warier, fearing it could drag the West closer to direct conflict with Russia.

"There are many sensitive issues to be discussed, the pros and cons," said Dutch Prime Minister Mark Rutte.

Polish premier Mateusz Morawiecki said that his country "will not be the first to hand over fighters" but would welcome others leading the way.

The Kremlin reacted with a grim warning.

"We see this as a growing engagement of Germany, UK, France in the conflict between Russia and Ukraine. The boundary between indirect and direct engagement is gradually disappearing. We can only regret it," spokesman Dmitry Peskov said.

He added that could "lead to an escalation of tensions" and would not change Russia's military objectives.

The NATO and the EU along with the United States have been the main backers of Ukraine since President Vladimir Putin's Russia unleashed a full-scale invasion on February 24 last year.

EU leaders touted the 67 billion euros ($72 billion) they have spent on military and financial aid to Kyiv, including funds spent on hosting four million Ukrainian refugees.

European Commission head Ursula von der Leyen pledged a new round of sanctions to punish Russian "propagandists" and cut another 10 billion euros worth off Moscow's exports.

Peace camp

French President Emmanuel Macron and German Chancellor Olaf Scholz both pledged that Europe would back Ukraine until its eventual victory.

But one leader sounded a different note. Hungary's Prime Minister Viktor Orban, the EU leader closest to Putin, did not applaud as Zelensky joined his colleagues for the group photo.

In a social media post, he said Hungary would send Kyiv humanitarian aid but called for an immediate ceasefire, rather than Ukrainian victory. "Hungary belongs to the peace camp!" he declared.

In frontline eastern Ukraine, the Lugansk regional governor warned that Russia was attacking Ukrainian forces near the town of Kreminna and "systematically destroying" three nearby communities.

Moscow says Russian forces were advancing on Bakhmut and Vugledar -- two key centres of fighting in the eastern Donetsk region of Ukraine, now the flashpoint of the war.