United States Army Secretary Dan Driscoll held talks late on Monday and Tuesday with Russian officials in Abu Dhabi as part of an intense new push by President Donald Trump’s administration to end the war in Ukraine, Driscoll’s spokesperson said.

US and Ukrainian officials are trying to narrow the gaps between them over a peace plan, with core issues still unresolved and Ukraine wary of being strong-armed into accepting a deal largely on the Kremlin’s terms.

“Late Monday and throughout Tuesday, Secretary Driscoll and team have been in discussions with the Russian delegation to achieve a lasting peace in Ukraine. The talks are going well and we remain optimistic. Secretary Driscoll is closely synchronised with the White House … as these talks progress,” said US Army Lieutenant Colonel Jeff Tolbert, a spokesperson for Driscoll.

The exact nature of the discussions was not immediately clear, and it was not known who was in the Russian delegation. A US official said that Driscoll, who has emerged as a point man for US diplomatic efforts on Ukraine, was also expected to meet Ukrainian officials while in Abu Dhabi.

Underlining the high stakes for Ukraine, its capital Kyiv was hit by a barrage of missiles and hundreds of drones overnight in a Russian strike that killed at least six people and disrupted power and heating systems. Residents were sheltering underground, wearing winter jackets, some in tents.

Will discuss sensitive issues with Trump: Zelensky

US policy towards the war has zigzagged in recent months.

A hastily arranged summit between Trump and Russian President Vladimir Putin in Alaska in August raised worries in Kyiv and European capitals that the Trump administration might accept many Russian demands, though it ultimately resulted in more US pressure on Russia.

The latest US peace proposal, a 28-point plan that emerged last week, caught many in the US government, Kyiv and Europe off guard and prompted fresh concerns that the Trump administration might be willing to push Ukraine to sign a peace deal heavily tilted toward Moscow.

The plan would require Kyiv to cede more territory, accept curbs on its military and bar it from ever joining Nato — conditions Kyiv has long rejected as tantamount to surrender.

The sudden push raises the pressure on Ukraine and President Volodymyr Zelensky, who is now at his most vulnerable since the start of the war after a corruption scandal saw two of his ministers dismissed, and as Russia makes battlefield gains.

Zelensky could struggle to get Ukrainians to swallow a deal viewed as selling out their interests.

He said on Monday the latest peace plan incorporated “correct” points after talks over the weekend in Geneva.

“The sensitive issues, the most delicate points, I will discuss with President Trump,” Zelensky said in his nightly video address.

Zelensky, who could visit the US in the next few days, said the process of producing a final document would be difficult. Russia’s unrelenting attacks on Ukraine have left many sceptical about how peace can be achieved soon.

“There was a very loud explosion, our windows were falling apart, we got dressed and ran out,” said Nadiia Horodko, a 39-year-old accountant, after a residential building was struck in Kyiv overnight.

“There was horror, everything was already burning here, and a woman was screaming from the eighth floor, ‘Save the child, the child is on fire!’”

Russian Foreign Minister Sergei Lavrov said an amended peace plan must reflect the “spirit and letter” of an understanding reached between Putin and Trump at their Alaska summit.

Macron warns against European capitulation

A group of countries supporting Ukraine, which is known as the coalition of the willing and includes Britain and France, was set to hold a virtual meeting on Tuesday.

“It’s an initiative that goes in the right direction: peace. However, there are aspects of that plan that deserve to be discussed, negotiated, improved,” French President Emmanuel Macron told RTL radio regarding the US-proposed plan. “We want peace, but we don’t want a peace that would be a capitulation.”

He added that only the Ukrainians could decide what territorial concessions they are ready to make.

“What was put on the table gives us an idea of what would be acceptable for the Russians. Does that mean that it is what must be accepted by the Ukrainians and the Europeans? The answer is no,” Macron added.

In a separate development, Romania scrambled fighter jets to track drones that breached its territory near the border with Ukraine early on Tuesday, and one was still advancing deeper into the Nato-member country, the defence ministry said.

Tensions have risen along Europe’s eastern flank in recent months after suspected Russian drones breached the airspace of several Nato states.