Russia vowed Thursday to take defensive measures against a missile defence system being developed by NATO and the United States, as top Western officials gathered in Romania to inaugurate a new US facility built for the shield.
Moscow believes that the system, which has been years in the making, could be used to shoot down Russian missiles. NATO argues that this is technically impossible. The United States, which has taken the lead in the project, says the system is actually meant to counter Iran.
The shield has been partly operational for several years, thanks to a radar in Turkey, a missile defence command centre in Germany and four US ships with interceptor missiles in southern Spain.
On Thursday, NATO and US officials inaugurated the system's first onshore site in the Romanian town of Deveselu. Home to interceptors and a radar system, it had already been activated back in December, but was declared "certified for operations" on Thursday.
Construction on a second onshore facility in Poland is due to start on Friday. Located near the Russian exclave of Kaliningrad, it is expected to become operational by 2018.
The Russian Foreign Ministry on Wednesday had slammed the shield's progress as "harmful" and a threat against "strategic stability."
"In the opinion of our experts, the deployment of this missile system represents a threat to the Russian Federation," Kremlin spokesman Dmitry Peskov added in comments carried Thursday by the state news agency TASS.
Russia has maintained that the system in Romania is too close to its borders and too far from Iran to justify the US claims.
Peskov also noted that "the situation with Iran has cardinally changed" recently and that the Iran issue "is losing its pertinence" given a recent warming in relations.
The Middle Eastern country signed a deal last year with six key powers to curb its nuclear activities. Since then, relations with Tehran have improved. But Iran has also been carrying out short and medium-range ballistic tests that have worried the West.
"It was never, ever about Russia. It was always about ballistic missiles coming out of the Middle Eastern region towards NATO allies and US forces in Europe," US Deputy Secretary of Defense Robert Work said following the inauguration ceremony in Deveselu.
NATO Secretary General Jens Stoltenberg added that "geography and physics" make it impossible for Russian intercontinental missiles to be shot down, arguing that the shield has too few interceptors and that they are "too far south or too close to Russia."
"NATO does not seek confrontation with Russia. We don't seek a new Cold War," Stoltenberg had said earlier Thursday during a visit to Bucharest. "The threats we have seen from Russia are unjustified, they are irresponsible."
Relations between NATO and Russia have already been severely strained due to the Russian annexation of Ukraine's Crimea peninsula and its support for separatists in eastern Ukraine.
The military alliance has stepped up its presence in eastern member states that say they feel threatened by Russia's actions, including Romania. Moscow has condemned the boost in NATO activities near its borders and taken countermeasures.
NATO is nevertheless now considering further reassurance measures to implement in its east. Romanian Prime Minister Dacian Ciolos said in Deveselu that his country would like to see a "large NATO presence" in the Black Sea.
Decisions are expected at NATO's next summit, due to be conducted in July in the Polish capital, Warsaw. The 800-million-dollar Deveselu facility, which was built by the US, is also expected to be placed under NATO control at the summit.
The new base will be "significantly increasing the defensive coverage of NATO territory against medium and short-range missile attacks," Stoltenberg wrote in an opinion piece published in the Romanian newspaper Adevarul on Thursday.
"We can never know for sure what challenges lie ahead. NATO's 67-year history has taught us that lesson well," he added. "But it has also taught us the value of being prepared to defend our nations from any threat at any time."