Updated: May 22
This is a developing story and is only offered as a brief analysis of a reported event.
A recent statement by Ukraine's security chief Oleksiy Danilov (via Sky News, AP, and others) has said that there was a night-time helicopter resupply drop to their forces in Mariupol. This is alleged to have brought weapons to the defenders of the embattled "Azovstal" factory.
While the source only cited weaponry, it is highly likely food and water was included given the length of time the Azovstal defenders have managed to defend the steelworks. For a helicopter to deliver these goods, they likely would have had to fly incredibly low (termed as Nape of the Earth), in an urban environment with an exceptionally dense enemy force presence.
While these factors cast doubt on this and frame it as a propaganda effort, the claim hasn't had the level of coverage as other notorious propaganda. It almost seems as if this ability is purposefully being kept under wraps so as to leave the opportunity to conduct further drops. Additionally, the identification of the aircraft being a helicopter may even be a misnomer in place of a large drone capable of evading eyesight and anti-air attack.
The ability to funnel arms, ammunition, food, and water is a game changer. It could pose a significant problem for Russian forces attempting to pacify the city, resulting in heavy human and equipment losses. While they have claimed to have captured the city entirely, many opposing reports say that Ukrainian defenders have been able to mount raids and ambush attacks on their foes. A resupply allows this destabilization of the occupation forces to continue, drawing soldiers and resources away from other would-be critical operations for the Russians.
Graphic of the underground tunnels and bunkers of the Azovstal steel plant.
These defenders have been completely encircled with virtually little to no meaningful contact or supplies from other units since the early days of the invasion. Many of the Ukrainian Marines also fighting for the city were forced to surrender, citing a severe shortage of ammunition and food stock.
While there has been a massive redeployment of Russian forces in the east of Ukraine, gains have been slow and bloody. As more European and American supplies are in route to the country, its likely both Russia and Ukraine will be locked in a static fight. Similar to the aftermath of the more covert 2014 invasion, each force will be forced to dig in to solidify gains and consolidate forces.