Ukraine defiant as key port Mariupol teeters on brink

The battered port city of Mariupol appeared on the brink of falling to Russian forces Sunday after seven weeks under siege, a development that what would give Moscow a crucial success in Ukraine following a botched attempt to storm the capital and the loss of the Russian navy's Black Sea flagship.

The Russian military estimated that about 2,500 Ukrainian fighters holding out at a hulking steel plant with a warren of underground passageways provided the last pocket of resistance in Mariupol. Russia gave another deadline for their surrender, saying those who put down their weapons were "guaranteed to keep their lives," but Ukraine remained defiant.

"All those who will continue resistance will be destroyed," Maj. Gen. Igor Konashenkov, the Russian Defence Ministry's spokesman, said. He said intercepted communications indicated there were about 400 foreign mercenaries along with the Ukrainian troops at the Azovstal steel mill, a claim that couldn't be independently verified.

Seizing Mariupol would free up Russian forces to weaken and encircle Ukrainian soldiers forces in eastern Ukraine, where Russia has focused its war aims for now and is deploying personnel and equipment withdrawn from the north after the failure to take Kyiv.

Ukrainian Deputy Defence Minister Hanna Malyar described Mariupol as a "shield defending Ukraine" as Russian troops prepare for a full-scale offensive in Donbas, the country's eastern industrial heartland where Moscow-backed separatists already control some territory.