American officials are rushing to finalize details ahead of Friday’s summit talks between Presidents Donald Trump and Vladimir Putin in Alaska, with both logistical and geopolitical issues still unsettled four days ahead of the momentous sit-down.

Unlike Putin’s military seizure of about a fifth of Ukraine, Russia’s 19th-century sale of Alaska to the US under Emperor Alexander II was a peaceful transaction. Still, it serves as a reminder that national borders are not set in stone, and land can be a currency for statecraft.

Washington’s push to negotiate an end to the war has raised concerns the Trump administration will make concessions to Moscow that Kyiv finds unacceptable.