Russian forces have moved closer to Mariupol and in addition to this, they have intensified their attacks along a front hundreds of kilometers long elsewhere in the Donbas, home to coal mines, metal plants and factories vital to Ukraine’s economy.

The Associated Press (AP) says If successful, the offensive would carve Ukraine in two.  

But analysts reportedly say it could also devolve into a grim war of attrition as Russia attempts to defeat Ukraine’s most experienced, battle-hardened troops who already have been fighting pro-Moscow separatist forces for eight years in the mostly Russian-speaking Donbas.

Meanwhile, a Ukrainian official said that Mariupol could fall into Russian hands within "hours."

A commander for the Ukrainian marines fighting Russian forces in Mariupol says his forces were may be facing their last days, if not hours.   

“The enemy is outnumbering us 10 to one,” Serhiy Volyna from the 36th Separate Marine Brigade said as he appealed for extraction from the last stronghold in Mariupol in a Facebook post early on Wednesday, according to Al Jazeera.

Russia’s Defense Ministry on Tuesday set another deadline for Ukrainian soldiers in Mariupol to surrender, saying the lives of the troops inside a steelworks will be spared if they stop what it called “senseless resistance”.

“All who lay down their arms are guaranteed to remain alive,” the ministry said in a statement on Tuesday, adding that troops would be able to withdraw from the steel plant between 2pm and 4pm Moscow time “without exception, without any weapons and without ammunition.”

Later in the day, the defense ministry said Russian forces had opened a humanitarian corridor so that Ukrainian troops who agreed to lay down their arms could leave the embattled city.

As fighting raged in the country's east and south, the president of the European Council Charles Michel arrived in Kiev, where he vowed the EU would do "everything possible" to help Ukraine win the war, ABC reported Wednesday.  

Michel's visit comes as the West continues to pour weapons into Ukraine amid a renewed Russian push into the eastern Donbas region where a new offensive launched this week has led to an uptick in fighting.

Meanwhile, Al Jazeera says Turkey has accused some of its NATO allies of wanting the war in Ukraine to last longer in order to weaken Russia.

“There are countries within NATO who want the war to continue,” Turkish Foreign Minister Mevlut Cavusoglu told CNN Turk in an interview.  “They want Russia to become weaker.”  He did not name any country directly.