The United States on Thursday criticized as "not constructive" Russian comments leaving open the possibility of targeting the Czech Republic and Poland if the US deploys a missile- defence system to the two former Soviet-bloc countries, according to dpa. First Deputy Prime Minister Sergei Ivanov on Wednesday said Russia could respond by placing missiles in the Russian enclave Kaliningrad if Washington does not instead accept a shared system in Azerbaijan proposed by President Vladimir Putin. "If our proposals are accepted, the need will disappear for Russia to deploy the new weaponry in the European part of the country, including in Kaliningrad, in order to react to the threat," Ivanov was quoted by Interfax news agency as saying in the Uzbek capital Tashkent. US State Department spokesman Sean McCormack on Thursday said Ivanov's remarks were "not constructive" but pledged the United States will continue to closely consult with the Russians on missile defence. "Mr Ivanov's comments were unfortunate, but I don't think it distracts us from the fact that we are having a constructive conversation with the Russians on the issue now," McCormack said. Russia opposes any US defence shield in its backyard, and Ivanov said Wednesday that the radar station planned for the Czech Republic could monitor Russia as well as Iran, one of the so-called "rogue states" the United States claims the defence shield is intended for. Putin offered wide-ranging cooperation with the US over the missile defence shield during a meeting with US President George W Bush on Monday in the state of Maine. Ivanov called Putin's proposals "ground-breaking" as they would place international relations on a completely new footing. Putin suggested including NATO and the European Union in the defence system. Putin also put forward a new offer of constructing a joint early- warning system in the southern Russian region of Krasnodar, replacing an earlier offer of using an ageing radar facility in Gabala in Azerbaijan.