KYIV, Ukraine • The U.S. and Germany pledged Wednesday to equip Ukraine with some of the advanced weapons it has long desired for shooting down aircraft and knocking out artillery, as Russian forces closed in on capturing a key city in the east.

Germany said it will supply Ukraine with up-to-date anti-aircraft missiles and radar systems, while the U.S. announced it will provide four sophisticated, medium-range rocket systems and ammunition.

The U.S. is trying to help Ukraine fend off the Russians without triggering a wider war in Europe. The Pentagon said it received assurances that Ukraine will not fire the new rockets into Russian territory. The Kremlin accused the U.S. of “pouring fuel on the fire.”

Western arms have been critical to Ukraine’s success in stymieing Russia’s much larger and better-equipped military, thwarting its effort to storm the capital and forcing Moscow to shift its focus to the industrial Donbas region in the east.

But as Russia bombards towns in its inching advance in the east, Ukrainian President Volodymyr Zelensky has repeatedly pleaded for more and better weapons and accused the West of moving too slowly. Andriy Yermak, the head of the Ukrainian president’s office, hailed the new Western weapons.

“I’m sure that if we receive all the necessary weapons and strengthen the efficient sanctions regime we will win,” he said.

The new arms could help Ukraine set up and hold new lines of defense in the east by hitting back at Russian artillery pieces that have been battering towns and cities and by limiting Russian airstrikes, said retired French Gen. Dominique Trinquand.