Ukrainian President Volodymyr Zelensky on Thursday pleaded for the joint support of the European Union and the United States once US President-elect Donald Trump retakes office.

"We need very much the unity between the United States and the EU, and the countries of Europe. This is very important,” Zelensky said, as he arrived at an EU leaders’ meeting in Brussels which he will attend as a guest.

"We need this unity to achieve peace,” he said, adding that only together could the US and Europe "really stop [Russian President Vladimir] Putin and save Ukraine.” Zelensky said he plans to discuss Washington’s support with Trump once he is back in office as having to do without US support would be "very difficult.” Ukraine is under increasing pressure as its armed forces face a difficult situation in eastern Ukraine and the possibility that Trump could try to push Kiev and Moscow into peace talks.

After more than 1,000 days of war and growing discussion of how the conflict could be ended, EU leaders continue to stress their commitment to help Ukraine in its defence against Russia’s invasion.

"The killing must come to an end. We have to get to a situation where peace is possible,” German Chancellor Olaf Scholz said.

For Scholz this means more military aid for Ukraine and no decisions without Kiev’s consent.

"The only way to get lasting and just peace is to put Ukraine in a position of strength,” said Estonian Prime Minister Kristen Michal, whose country shares a border with Russia.

"That means that Ukraine needs assistance, money, weapons, air defence, everything we can provide, everything Europe and the States can [provide].” "Any push for negotiations to soon will actually be a bad deal for Ukraine,” warned EU top diplomat Kaja Kallas.

"All the other actors in the world are carefully watching how we act in this case, and therefore we really need to be strong,” she stated.

The EU summit "is an important occasion to send a united and unequivocal message of support to Ukraine, for a comprehensive, just and lasting peace,” said new European Council President António Costa ahead of the meeting.

EU leaders are likely to promise increased military aid, including the delivery of air defence systems, ammunition and missiles, as well as more training and equipment for Ukraine’s army.

At the last scheduled EU summit before Trump returns to the White House on January 20, leaders are also expected to stress that no initiative to end the conflict should be taken without Ukraine.

Zelensky’s meeting with EU leaders comes a day after he met with NATO Secretary General Mark Rutte and some European leaders in Brussels to discuss further military support. (DPA)