US Secretary of State Antony Blinken says that President Vladimir Putin's decision to send reinforcements to Ukraine's Kharkiv region underlines the huge losses Russia's forces are taking in its war. Separately, he says that Iran's latest reply on a nuclear deal is a step "backwards," insisting Washington would not rush to rejoin at any cost. Blinken was speaking to reporters at NATO headquarters in Brussels after talks with the Western alliance's Secretary General Jens Stoltenberg, one day after the chief US diplomat had visited Kyiv. IMAGES AND SOUNDBITES