Russian forces took parts of the eastern Ukrainian city of Severodonetsk on Tuesday following street fighting with Ukrainian defenders, boosting Moscow’s control over one of Kyiv’s most important strongholds in the Donbas area, the recent focus of its Ukraine offensive.

Russia has intensified its push to take the strategically important city as Western leaders have taken new measures to punish Moscow for its invasion. The Biden administration plans to provide Ukraine with precision-guided rocket systems to boost Ukraine’s firepower against Russian troops.

It is unclear how many of the new systems, which U.S. officials say can hit targets from a distance of 40 miles or more, the U.S. would provide, but one official said they could arrive in Ukraine within weeks. Training on how to use them would begin quickly and would take at least 10 days.

Analysts say that while Ukrainians have learned to use the individual weapons systems, they will be much more effective when they are able to use them in concert. Western governments have hoped that the steady flow of weapons to the Kyiv government could change the calculus of the battle in eastern Ukraine, where Russia wants to capture Donbas, once Ukraine’s industrial heartland, which borders Russia.