The EU has dismissed Vladimir Putin’s suggestion that the Kremlin-friendly former German chancellor Gerhard Schröder could serve as a European mediator in peace talks aimed at ending the war in Ukraine.

Over the weekend, the Russian leader put forward Schröder – a longtime ally – as a possible figure to help restart talks with Europe, saying he would “personally” favour the former German leader for the role.

Schröder, 82, previously held senior positions in Russian energy projects, including work on the Nord Stream gas pipelines and a seat on the board of Russian oil company Rosneft. He stepped down from the role several months after Moscow’s full-scale invasion of Ukraine, under mounting pressure, but has never explicitly condemned Putin over the invasion.

Responding to the proposal, Kaja Kallas, the EU’s top diplomat, told journalists in Brussels before a meeting of foreign ministers: “First, if we give Russia the right to appoint a negotiator on our behalf, that would not be very wise.”

Kallas said Schröder could not be considered an impartial mediator given his past work as a “high-level lobbyist for Russian state-owned companies”. She said: “It is clear why Putin wants him to be the person, so that actually he would be sitting on both sides of the table.”

The Russian president suggested the conflict in Ukraine could be drawing to a close – a rare instance in which Putin appeared to hint at a possible timeline for ending the invasion. But his top advisers have said the Kremlin continues to demand that Ukraine withdraw its troops from the eastern Donbas region as a precondition for future negotiations.

Putin remains determined to seize the remaining parts of the region by force this year before any serious talks begin, people familiar with his thinking have told the Guardian. Ukraine has flatly rejected any suggestion it would unilaterally withdraw from its own territory, a position bolstered by recent battlefield dynamics in which Russian advances have largely ground to a halt.

The two armies are showing mounting signs of exhaustion and continuing to sustain heavy casualties, while trading strikes on each other’s energy infrastructure. Against that backdrop, analysts say a diplomatic breakthrough is unlikely.

Germany’s defence minister, Boris Pistorius, suggested Putin’s peace remarks were likely to be a ruse. “If he sees the end of this war approaching, couldn’t he simply end it himself? Then he would have control over the timing,” Pistorius said during a visit to Kyiv. “Instead, as always, he sets conditions. It’s to be feared – and I hope I’m wrong – that this is yet another deception. But it can’t be ruled out, and it seems to be part of his hybrid war strategy,” he added.

The defence minister said Putin, “was trying to divert attention from his own weaknesses”.

A US-brokered ceasefire is due to expire on Tuesday and Moscow has rejected prolonging the truce. But EU leaders have in recent months stepped up efforts to secure the bloc a seat at the table in any future substantive peace negotiations.

European capitals have long insisted that no discussions or decisions about Ukraine should take place without Kyiv’s involvement. Many across the continent now fear that talks between the US, Russia and Ukraine aimed at ending the more than four-year-long war have made little progress, while leaving the EU increasingly sidelined and vulnerable to pressure to accept a deal it does not support.

There is little prospect of Schröder emerging as Europe’s representative with the Kremlin. His record of defending Moscow has repeatedly put him at odds with mainstream European opinion. After evidence of mass killings emerged in the Kyiv suburb of Bucha in April 2022, he said he did not believe the massacre had been ordered by the Kremlin.

Germany’s Europe minister, Gunther Krichbaum, said Schröder had “not necessarily demonstrated in the past that he could act as a neutral mediator, as an honest broker, so to speak”, as he was “heavily influenced” by Putin.

“Close friendships may be legitimate everywhere in the world, but they don’t contribute to being perceived as an honest negotiating partner,” he added.

Margus Tsahkna, Estonia’s foreign minister, said: “Gerhard Schröder is Putin’s idea. I think they are very close. Gerhard Schröder will not be representing Europe.”

Mark Galeotti, an expert on Russian politics, described the suggestion as a “classic Putin idea”. “He tries to sound reasonable, but frames any potential dialogue in terms most comfortable to him,” Galeotti told Times Radio.

Schröder has not publicly commented on the idea.