Kiev, July 28 : Ukraine's campaign to retake Kherson, the southern city which was the first to fall to Russia in March, is "gathering pace", according to Western military sources. The sources described Kherson as "politically the nearest Russia has to a jewel in the crown of its occupation", and its loss, they say, "would severely undermine Russia's attempts to paint the occupation as a success", the BBC reported. The key Antonivskiy Bridge into Kherson was forced to shut on Wednesday after being damaged by a Himars artillery rocket system fired by Ukrainian forces. The attack left the crossing "completely unusable", the sources said. Moscow depended on the crossings to resupply their troops stationed west of the river, and are now at risk of becoming isolated from the rest of Russia's occupying forces, they added. Meanwhile, Russian officials posted in Kherson also confirmed that a Ukrainian artillery strike had seriously damaged the Antonivskiy Bridge, forcing its closure to traffic. For days the Ukrainian military has targeted bridges using highly effective rocket systems supplied by the US, reports the BBC. According to the Western military sources, Wednesday's attack was part of a Ukrainian counter effort to isolate Russian troops, with the ultimate goal of recapturing the entire Kherson region. In his nightly Wednesday address, President Volodymyr Zelensky vowed that Ukraine would eventually rebuild the Antonivskiy Bridge as well as other crossings in the Kherson region. "We are doing everything we can to ensure that the occupiers' logistical operations on our land are thwarted. Whatever their plans are, we will prevent their realisation," Ukrayinska Pravda quoted Zelensky as saying The President stressed that Ukraine will liberate its territory "with military, diplomatic and every other tool at its disposal". /IANS