(Dan Tri) – Ukraine’s Commander-in-Chief warned of upcoming `major battles` in Kharkov after Russian President Vladimir Putin announced that Russia sought to establish a security buffer zone in this area.

Ukraine’s defense forces are being stretched when Russia opens a new front in Kharkov (Photo: New York Times).

`We understand that there will be fierce battles and the enemy is preparing for that,` Commander-in-Chief of the Armed Forces of Ukraine Oleksandr Syrskyi commented on Telegram on May 17.

He added that Russian forces have expanded the combat zone in Kharkov by 70km.

General Syrskyi said, the Ukrainian army is also preparing defense lines for a potential Russian attack on the Sumy region, more than 100km north of Kharkov.

An expanding front line especially challenges Ukraine at a time when the country’s military resources are exhausted and it is waiting for more aid from the West.

Mr. Syrskyi’s comments came after President Putin said on May 17 that, at the present time, Russia has no plans to control the city of Kharkov, instead, Moscow wants to set up a buffer zone to protect

`Everything that is happening in Kharkiv is their (Ukraine’s) fault, because they have been shelling settlements on Russia’s borders, including the Belgorod region. I have said publicly that

Russia began attacking Kharkov again on May 10 after nearly 2 years of being pushed back from this territory.

The Russian Ministry of Defense announced that to date, their army has controlled 12 villages in Kharkiv.

With overwhelming force and firepower, Russia attacked quite quickly in Kharkov.

The Washington Post newspaper, citing data from the US-based Institute for the Study of War (ISW), also said on May 17 that, in the past 6 weeks, Russia controlled more territory in Ukraine than Ukraine did in the past 6 weeks.

Since the beginning of this year, Russia has controlled 553 square kilometers of Ukrainian territory, of which 294 square kilometers have been occupied since the beginning of April alone.

British intelligence warned Ukraine in advance of a Russian attack on Kharkov, but said Kiev had not prepared better defenses.

Russian forces continued to advance even as Ukraine sent dozens of additional units to reinforce Kharkov.