LAQUILA, Italy, (Reuters/AFP) - Russian President Dmitry Medvedev renewed a threat on Friday to deploy missiles in Russias exclave of Kaliningrad near Poland if Washington goes ahead with its missile shield plans in Europe. In sharp contrast to his positive words during President Barack Obamas visit to Moscow earlier this week when the two reached broad agreement on nuclear arms cuts, Medvedev used a news conference at the G8 summit to return to Russias earlier tough rhetoric on arms control. If we cannot agree on this question (missile defence) then you know the consequences, he told reporters after a G8 summit in LAquila central Italy. I have nothing to add and what I said in my address to the nation remains valid. Medvedev also appeared to change his tone on the missile defence shield itself, and during Obamas visit to Russia, he told the US leader, using markedly softer language than normal, that no one is saying that missile defence is harmful in itself or that it poses a threat to someone. But in Italy on Friday, Medvedev returned to the Kremlins traditional posture on the system, describing it as harmful and threatening to Russia.