"There are still our military forces, our soldiers so they will fight until the end and as for now they are still in Mariupol," ABC News quoted Ukrainian Prime Minister Denys Shmyhal as saying.

Meanwhile, an adviser to the mayor of Mariupol has also rejected the Russian ultimatum. According to CNN, Russia's Ministry of Defense had called on the Ukrainian soldiers still in Mariupol to surrender by 1 pm (local time), warning that anyone still resisting after the deadline "will be eliminated."

Later, the ministry said that the surrounded Ukrainian soldiers "were offered to voluntarily lay down arms and surrender in order to save their lives."

"However, the Kyiv nationalist regime, according to the radio intercept, forbade negotiations about surrendering," the Ministry claimed.

It quoted the Ukrainian soldiers, who had previously surrendered, that "there are up to 400 foreign mercenaries who joined the Ukrainian forces" trapped at the plant, including Europeans and Canadians.

"In case of further resistance, all of them will be eliminated," it added.

(With UNI inputs)