For Ukraine to withdraw from western Donetsk would mean the grievous loss not just of land, with the prospect of a new exodus of refugees, but the fall of a bulwark against any future Russian advance. Here we look at why the territory matters so much.

Russian troops currently control about 20% of Ukrainian territory, but the Ukrainian constitution forbids giving up territory or trading land.

Putin seeks "a multilateral system of commitments that includes not only the West but also Russia itself," one expert told Newsweek.

Security guarantees have become a central focus in discussions about a peace deal for Ukraine, with the country’s President Volodymyr Zelensky saying at the White House Monday that they are the “key issue,

The US president says Russia's Vladimir Putin would face a "rough situation" if he doesn't co-operate in the peace process.

Major questions remain over what both sides might accept after Trump held successive talks with Putin and Zelensky.

As negotiations over the war carry on, President Vladimir V. Putin is pushing hard with tactics that have evolved over three and a half years.