The United States, Russia and Ukraine rarely agree on anything. But as their delegations meet in Abu Dhabi for their first trilateral meeting since Russia launched its full-scale invasion of Ukraine, the three parties seem to have come to the same conclusion: Only one issue remains to be resolved.

That issue is territory, namely the eastern Ukrainian region known as the Donbas. And based on their comments coming into the meeting, it is unlikely to be resolved.

“It’s all about the eastern part of our country, it’s all about the land,” Ukraine’s President Volodymyr Zelensky said, pointing to Russia’s long-standing – and previously rejected – demand that Kyiv gives up the parts of the Donbas it still controls.

While US President Donald Trump has touted a deal being close, Zelensky reiterated Thursday that Ukraine was not ready to hand over parts of its territory to Russia. And speaking after a meeting with Trump’s special envoy Steve Witkoff on Thursday, Kremlin aide Yury Ushakov made it clear Russia was also not willing to compromise.

He warned that there wouldn’t be any long-term settlement “without resolving the territorial issue,” repeating the threat that Russia would continue to pursue its goals “on the battlefield” until an agreement is reached.

Collectively known as the Donbas, the two coal-rich eastern Ukrainian regions of Donetsk and Luhansk used to be Ukraine’s industrial heartland.

A steel manufacturing powerhouse, the region is well connected to the Sea of Azov by rivers and man-made canals. It is also known for its fertile agricultural ground and rich mineral deposits.

Russian President Vladimir Putin has made no secret of the fact that he doesn’t believe Ukraine has the right to exist as an independent country – dismissing the sovereignty it gained in 1991 following the break-up of the Soviet Union.

He has claimed that Ukraine and Ukrainians are part of a larger “historical Russia” and has repeatedly – without any evidence – accused Kyiv of conducting “genocide” against Russian speakers in Ukraine.

Historically the Donbas was the most “Russian” part of Ukraine, with a significant Russian-speaking population living there. And it was in the Donbas that Putin’s mission to destabilize and conquer Ukraine started in 2014.

In 2014, Russia illegally annexed the southern Ukrainian peninsula of Crimea, following a covert military operation led by highly trained Russian soldiers who were not wearing any insignia.

At the same time, Russia began backing and supplying pro-Russian separatists in the Donbas, helping them seize control of parts of Luhansk and Donetsk, including their regional capitals, from what was then an ill-prepared and poorly motivated Ukrainian military.

Russia has long maintained that it had no soldiers on the ground there, but United States, NATO and Ukrainian officials all say the Russian government supplied the separatists, provided them with advisory support and intelligence, and embedded its own officers in their ranks.

In one particularly horrific incident, the separatists used a Russian-provided Soviet-era Buk surface-to-air missile to shoot down a civilian flight MH17, killing 298 people. Moscow has repeatedly denied responsibility, but a Dutch court found two Russians and a separatist Ukrainian guilty of mass murder for their involvement in MH17’s destruction.

For almost eight years a low-intensity war simmered along the frontlines in the Donbas, claiming the lives of some 14,000 people, according to Ukrainian figures.

Then, in February 2022, Putin announced that Russia would recognize the so-called Donetsk People’s Republic (DPR) and Luhansk People’s Republic (LPR) as independent states.

Three days later, he launched a full-scale invasion of Ukraine.

Putin has spent almost 12 years trying to take control of the Donbas by military means.

But while the Russian military vastly outmans and outguns the Ukrainians, Moscow has so far failed to seize the region in its entirety. While Russian troops control almost all of Luhansk region, they’ve only managed to seize 70% of Donetsk, despite committing huge resources to the fight.

It is the remaining portion of Donetsk that Russia is determined that Ukraine relinquishes. About two-thirds of that land is controlled by Ukraine, while one third is a no-man’s land where fighting continues.

Putin and his aides have repeatedly threatened to take the territory by force if Kyiv doesn’t give it up. But the progress along the front line has been very slow and costly. NATO’s Secretary General Mark Rutte said last week that an estimated 20,000 to 25,000 Russian soldiers are being killed every month. Russia does not disclose its casualty figures.

The Institute for the Study of War, a US-based conflict monitor, estimates that at the current rate of gains it would take Russia another year and half to take over the remaining parts of the Donbas under Kyiv’s control.

Zelensky has repeatedly stressed that permanent territorial concessions are non-negotiable. Even if the Ukrainians were to vote in favor of giving up their land – which they are unlikely to do, according to public opinion polls – the agreement would still be illegal under international law, which prohibits the use of force to conquer another state’s territory.

Instead, Kyiv, backed by the Europeans, has indicated that it would be willing to recognize the current reality on the ground in a potential ceasefire deal, in order to stop the killing.

This would likely mean freezing the conflict along the existing front lines and essentially giving up on trying to regain its land while the ceasefire is in place.

But losing the rest of the Donbas would also make Ukraine much more vulnerable toward any future Russian aggression. The area contains the “fortress belt” of industrial cities, railways and roads that form the backbone of Ukraine’s defense and supply the frontline.

Kyiv has spent years fortifying this area and losing it would leave the rest of eastern Ukraine wide open.

Details of the latest proposal have not been made public, with Zelensky saying the meeting in Abu Dhabi could provide “variants.”

But the Ukrainian leader said in December that one proposal put forward by the US was to create a “free economic zone” in the parts of the Donbas region that are still under Ukraine’s control. He said that the proposal would see Ukraine withdrawing from those areas in exchange for security guarantees.

The US has not revealed any details about the proposal, and it is unclear whether Russia would accept it – Ushakov’s words about territory ahead of the meeting in Abu Dhabi did not indicate a willingness to compromise.

International human rights organizations and survivors who have managed to escape, as well as Ukrainian authorities and media organizations, including CNN, have chronicled numerous human rights abuses across Russian-occupied regions of Ukraine.

The allegations include arbitrary detentions, enforced disappearances, torture, sexual violence and a complete clampdown on civil rights. Russia denies the accusations, despite ample evidence.

The latest United Nations report on the human rights situation in Ukraine, published in November, assessed that the “Russian occupying authorities continued to restrict civilians’ rights and violate fundamental provisions of international humanitarian law.”

Ukrainians living under Russian occupation have told CNN they are being forced to accept Russian passports or risk losing their homes, that their children are being indoctrinated in schools and special “re-education” camps, and that any attempt to resist is punished with violence.