Russian President Vladimir Putin has said the operation to liberate the Ukrainian city of Mariupol is "complete" and a "success."

The Russian government announced on Thursday Defence Minister Sergei Shoigu reported to Putin that their forces have seized the key port city in southeastern Ukraine.

Shoigu said that Mariupol has been "liberated" and the entire city is now under the control of Russian forces and pro-Russian separatists.

The minister explained that more than 2,000 Ukrainian troops remain inside the city's steel plant.

Putin congratulated Shoigu and instructed him to cancel plans to storm the industrial zone, saying he considers it unnecessary.

But the President told his military to continue encircling the area saying, "Block off this industrial area so that not even a fly can get through."

The Russian military has intensified its offensive on Mariupol on the Sea of Azov since it began the invasion on February 24.

Moscow claimed on Saturday that its military had besieged the steel plant where remaining Ukrainian troops were holed up.

Ukrainian forces have rejected several Russian demands to lay down their weapons and surrender.

Mariupol is a strategically important city for both sides.
Moscow wanted the port city to complete a corridor connecting Russian-annexed Crimea and the eastern region of Donbas that pro-Russian militants have effective control on most parts.

Military analysts have pointed out that Putin aims to demonstrate victory by seizing the city ahead of the May 9 anniversary, marking the Soviet victory over Nazi Germany.