Syrian rebel leaders are in secret talks with Russia to end the fighting in Aleppo, according to opposition figures, a development that shows how the US could become sidelined in some of the Middle East’s most pivotal conflicts.

Four opposition members from rebel-held northern Syria told the Financial Times that Turkey has been brokering talks in Ankara with Moscow, whose military intervention last year on the side of President Bashar al-Assad helped turn the five-year civil war in the regime’s favour.

The talks, they say, have focused on negotiating a deal to end the conflict in Aleppo, the country’s besieged second city.

“The Russians and Turks are talking without the US now. It [Washington] is completely shut out of these talks, and doesn’t even know what’s going on in Ankara,” said one opposition figure who asked not to be identified because of the sensitivity of the negotiations.

While this is not the first time a rebel representative has met with the Russians, those familiar with the talks said it is the first time such a large number of opposition groups were involved — a sign of where they think they will have to turn to reach a deal.

Talks appear to have made little progress, but the fact they are taking place — without US involvement — underlines the shifting political dynamics in the Middle East.

President-elect Donald Trump has repeatedly signalled his willingness to back Russian President Vladimir Putin’s efforts to shore up the Assad regime in the five-year civil war, arguing the Kremlin is acting to stamp out Islamic extremists. The outgoing Obama administration has provided training and weaponry for the rebels and has called for Mr Assad’s departure.

Regional actors now seem more willing to bypass Washington to seek out pacts with Russia, which is keen to develop the image of a rising power that can help broker such deals.

Ali Sheikh Omar, an Aleppo council leader, said politicians in rebel-held eastern districts have agreed a team they want to join negotiations with Russia over ending the fierce aerial assault that has flattened the city. Regime forces have made a significant breakthrough in the past week, captured more than a third of the rebel’s territory in the city.

“Negotiations are being done directly with the Russians because we all know at this point that Bashar al-Assad is nothing more than a provincial governor carrying out the orders of Putin,” he said.

One rebel leaders denied such negotiations, while others declined to comment saying the issue was too sensitive. A western regional diplomat said he had no confirmation but had been seeking information about potential talks. He also had reports of a Russian military flight from the Syrian port city of Latakia, the site of one of Moscow’s military bases, to Ankara on November 24.

None of those who spoke about the negotiations would clarify if the rebels met the Russians face-to-face or indirectly, with Turkish officials mediating.

Asked about the talks, Maria Zakharova, a Russian foreign ministry spokeswoman, said: “Washington isolated itself. We’ve been negotiating with the [Syrian] opposition in Turkey for years — it’s not news.” A Turkish official did not respond to a request for comment.