WASHINGTON, May 31 - President Joe Biden said in a guest essay Tuesday evening in The New York Times that he’s decided to provide the Ukrainians with more advanced rocket systems and munitions that will enable them to more precisely strike key targets on the battlefield.

The expectation is that Ukraine could use the rockets in the eastern Donbas region, where they could both intercept Russian artillery and take out Russian positions in towns where fighting is intense, such as Sievierodonetsk, The Associated Press reported.

That town 90 miles (145 kilometers) south of the Russian border is in an area that is the last pocket under Ukrainian government control in the Luhansk region of the Donbas.

In his New York Times’ essay, Biden said the U.S. is not encouraging or enabling Ukraine to strike beyond its borders and does not want to prolong the war “just to inflict pain on Russia.”

U.S. officials familiar with the decision did not detail how much the aid will cost, but it will be the 11th package approved so far and will be the first to tap the $40 billion in assistance recently passed by Congress.

A regional governor on Tuesday said Russian troops have won control over most of a city that has been the epicenter of fighting in eastern Ukraine.

Luhansk Gov. Serhiy Haidai said “most of Sievierodonetsk is under the Russian control.” He added in a messaging app statement that Ukrainian forces continued to fight the Russians in fierce street battles and said the city has not yet been surrounded.

Sievierodonetsk, the administrative center of the Luhansk region, has been the focus of Russia’s offensive in Ukraine’s eastern industrial heartland of Donbas. It has come under relentless Russian bombardment.

Haidai said that Tuesday’s Russian air strike hit a tank with nitric acid at a chemical factory, releasing toxic fumes. (ap/ez)