The Kremlin on Wednesday vowed to respond with countermeasures if Ukraine used cluster bombs against its invading troops after the United States pledged the weapons to Kyiv.The potential use of this type of munitions changes the situation, and of course, it would force Russia to take countermeasures, Kremlin spokesman Dmitry Peskov told reporters, without clarifying what such countermeasures would entail.Last week, Washington pledged to deliver cluster bombs to Kyiv as it conducts a counteroffensive against Moscows forces.Russia itself uses the controversial munitions in Ukraine but they are banned in many parts of the world.Humanitarian groups have strongly condemned the United States decision to supply cluster bombs, which can go undetonated and potentially endanger civilians for years.United States President Joe Biden admitted that supplying Ukraine with weapons capable of covering several football fields with hundreds of multiple small explosives was "a difficult decision."AFP contributed reporting.