Volkswacht Bodensee - US plan sees Ukraine joining EU in 2027, official tells AFP

The complicated EU accession process usually takes years and requires a unanimous vote from all 27 members of the bloc, and some countries, most notably Hungary, have consistently voiced opposition to Ukraine joining.

The idea of a speedy accession is included in the latest version of a US-led plan to end the war, which would also see Ukraine cede land to Russia, and has triggered a diplomatic frenzy across Europe in recent weeks.

"It's stated there but it's a matter for negotiation, and the Americans support it," the senior official, speaking on condition of anonymity, said, referring to the US plan.

Washington has the leverage needed to convince leaders opposed to Ukraine's membership to change their stance, President Volodymyr Zelensky told journalists, including AFP, on Thursday.

"The United States can take steps to unblock our path to the European Union," he said, adding that "the US president has various levers of influence and that this will have an effect on those who are currently blocking Ukraine."

Kyiv has long strived for EU membership and has been implementing reforms since a pro-European 2014 revolution but has struggled to eradicate endemic corruption -- a core prerequisite for joining the bloc.

After completing a diplomatic tour across Europe last week, Zelensky was due in Berlin on Monday for more talks on the plan, full details of which have not been released.

"If the security situation allows, he'll be there", the senior official told AFP.

- A long road -

Moscow on Friday indicated it was suspicious about the efforts to amend the US plan, which it has largely been supportive of and heeded to most of its core demands.

"We have an impression that this version, which is being put forward for discussion, will be worsened," Kremlin foreign policy aide Yuri Ushakov told the Kommersant business daily.

"It'll be a long process," he added, saying that Moscow had not seen an updated version of the plan since discussions between Russian President Vladimir Putin and US envoys Steve Witkoff and Jared Kushner in Moscow last week.

Zelensky said Thursday that Washington wants only Ukraine, not Russia, to withdraw its troops from parts of the eastern Donetsk region, where a demilitarised "free economic zone" would be installed as a buffer between the two armies.

Russia, which has the numerical advantage in manpower and weapons, has been grinding forward on the battlefield for months, notching up its quickest advance for a year in November.

However on Friday, Ukraine claimed to have retaken two settlements near Kupiansk -- a strategically important city and a key railway hub in the northeast of the country.

Zelensky visited the troops near Kupiansk to congratulate them -- and recorded a video of himself on a road at the entrance to the southwest of the city.

The Russian army currently occupies about 20 percent of Ukrainian territory in the east and south, which has been decimated by years of fighting.

The war has killed tens of thousands and forced millions to flee their homes.

T.Zimmermann--VB