Ukraine's President Volodymyr Zelensky, center, gestures as European Parliament's President Roberta Metsola, right, applauds during an EU summit at the European Parliament in Brussels, Belgium, February 9, 2023. (AP)

Ukraine's President Volodymyr Zelensky attended a meeting of the EU parliament in Brussels on Thursday and addressed European MPs.

His last-minute previously unannounced trip, the second overseas travel after visiting Washington last December, came following a European short tour to the UK and France on Wednesday, where he was lobbying for more weapons, including fighter jets and long-range missiles.

"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 the parliament.

Roberta Metsola, the President of the EU parliament, said in an address to Ukraine's leader, "Ukraine is Europe and your nation's future is in the European Union."

"States must consider, quickly, as a next step, providing long-range systems and the jets you need to protect the liberty too many have taken for granted," she added.

Zelensky to EU summit: We have to bolster the dynamics of our cooperation

Following his address to the parliament, Zelensky attended the regular European Council summit consisting of the heads of the member states as a special guest.

"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 the heads of state.

"We have to enhance the dynamics of our cooperation, we have to do it faster than the aggressor," he added, referring to the supply of combat jets and long-range missiles.

Estonian Prime Minister Kaja Kallas stated that "it's very important that we speed up military aid to Ukraine. I think all of us looked in the warehouses at what we have. But we should do more."

Russia warns the West

Commenting on Kallas' remarks, the spokesperson for the Russian Kremlin said, "We [Russia] 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."

"The actions of these countries lead to an escalation of tensions... make this conflict more painful... and these actions will not change the objectives of our country within the framework of the special military operation," Spokesperson Dmitry Peskov added.

During Zelensky's trip to the UK, British Prime Minister Rishi Sunak showed Ukraine's President the Challenger 2 battle tanks that his country will be sending to Kiev, in addition to German-made Leopard 2 tanks that will be supplied by Germany and other countries.

Upon his arrival at the summit, German Chancellor Olaf Scholz said, "We [EU heads of states] are gathered here today to give a sign of solidarity and unity."

"We can send out this signal once again and show that we will continue our support for Ukraine in defending its independence and integrity for as long as necessary," Scholz added.

Zelensky's European trip comes as Russian forces are advancing on the Bakhmut front with full force.

Last Sunday, the founder of the Russian military company Wagner Group, Yevgeny Prigozhin, who is fighting in the war in Ukraine, said that battles for the city of Bakhmut, also known as Artyomovsk, are being fought for each street and house.

"Let me clarify the situation. The Ukrainian armed forces are not retreating anywhere. They fight to the last. Fierce battles are waged for every street, house, and stairwell in the northern quarters of Artyomovsk," he told reporters.

Bakhmut, located north of Donetsk, has been a battleground for months. During the war in Ukraine, it served as a critical transportation hub for Ukrainian troops stationed in Donbass.

Earlier in January, Prigozhin announced that Soledar was now under the control of Russian forces.

"For the offensive, we need more armoured vehicles and ammunition," the statement said.