Top US and Russian diplomats made little progress in resolving disagreements over Washington's controversial plans to install a missile defence system in former Soviet satellites the Czech Republic and Poland during talks in Budapest Thursday, according to dpa. Acting Undersecretary for Arms Control and International Security John Rood, heading up the US delegation, said that the latest talks were mainly aimed at exchanging intelligence in order to ease Russian fears. "We had a serious discussion on the perception of the missile threat as it is today and how it will develop," he told journalists after the meeting. "This is the most detailed intelligence exchange we've ever had with our Russian colleagues." The meeting was the fifth in a series of sometimes-stormy talks with Russia on the plans, which Moscow claims could eventually threaten its own security. Russian President Vladimir Putin in October suggested the US plans were as dangerous as the Cuban missile crisis at the height of the Cold War and has issued a counter-proposal that the US could use a Russian radar site in Azerbaijan and facilities in southern Russia. Rood said that the talks were helping each side understand the other's position with regard to threat perception, although he admitted that there were "differences in approach" in analysing the situation. The US claims that the mooted missile-defence system, which is expected to see a radar site in The Czech Republic and a launch site in Poland, is aimed at a possible threat from states such as Iran and North Korea. Rood said that the US delegation attempted to show the Russians that the missile defence system was purely aimed at this threat. "We explained why we don't think it poses a threat to Russian security - it is not aimed at Russia and we think it does not have the capability to intercept long range missile launches from Russia," he said. A recent CIA intelligence report, which revealed that Iran stopped its nuclear weapons programme in 2003, could potentially undermine the US government's argument, but Rood said the while the issue was briefly discussed it made to no difference to system. "We are concerned about ballistic missile programmes...this week we saw the Iranian Defence Minister making a statement on the development of a new ballistic missile system," he said. "We would be concerned about the development of this system, regardless of the type of payload." The latest meeting came amid mounting East-West security tensions and a day after Russia suspended participation in a key Cold War treaty limiting armed forces in Europe. Russia has suspended all activities toward observing the treaty on Conventional Armed Forces in Europe (CFE), the Russian Foreign Ministry said in a statement Wednesday. Rood said he told Russian Deputy Foreign Minister Sergei Kislyak, leading the Russian delegation, that the US was disappointed at the decision. "I did register the concerns of the US government with the action taken by Russia. The US deeply regrets Russia's decision to suspend its obligations under the CFE treaty," he said. "It (the treaty) has demonstrated its importance with impressive reductions in military build up in Europe," he continued. "We encourage Russia to reverse its decision." The US is still in talks with Prague and Warsaw on the proposed sites, and Rood said he was travelling to Prague on Friday to continue talks with the Czech government. He also said he expected talks with Poland to resume once the new Polish government had "got its feet on the ground". Addressing concerns that the European missile defence system is aimed at a vague distant threat, he pointed to events last summer, when the US activated its multi-billion-dollar domestic missile defence system for the first time. "North Korea beginning stacking a long-range missile with an unknown payload they refused to clarify," he said. "People were urging the US to conduct a pre-emptive strike but we didn't consider it." "For the first time we activated our missile defence system...this proved stabilizing because we didn't have to add fuel to the fire."