Avdiivka is at risk of falling into Russian control

 The US has warned that Russia could seize Ukraine's key eastern town of Avdiivka - the scene of some of the fiercest fighting in recent months.

"Avdiivka is at risk of falling into Russian control," National Security Council spokesman John Kirby said, citing Ukraine's ammunition shortages.

Ukrainian President Volodymyr Zelensky vowed to do everything to "save as many Ukrainian lives as possible".

Russian troops have made gains in Avdiivka, threatening to encircle it.

The town - which has been almost completely destroyed - is seen as a gateway to nearby Donetsk, the regional Ukrainian capital seized by Russian-backed fighters in 2014 and later illegitimately annexed by Moscow.