NATOchief Jens Stoltenberg said onMonday that amassivetransfer of US and allied troops to EasternEuropeas part of a military exercise was not aimed atRussia.
About 37,000 soldiers from 18 countries are to participate in the US-run manoeuvre dubbed DefenderEurope2020.
This is "the largestdeploymentof US troops toEuropein more than 25 years," Stoltenberg said.
The exercise "shows the strong US commitment toNATOand to the freedom and security ofEurope," he added.
The exercise will take place in May and June, mainly in Germany, Poland and the Baltic States.
The US will move 20,000 soldiers toEuropein the coming months.
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"DefenderEuropeis not directed against any particular country," Stoltenberg said.
"This defensive exercise demonstrates the ability to rapidly move a large force from the United States toEuropeto help protect otherNATOAllies if needed," he said.
The exercise comes amid doubts over whether the US is still prepared to defendEurope.
After his inauguration, US President Donald Trump initially describedNATOas "obsolete".
But after Germany and the other European members pledged higher defence spending, Trump reaffirmed his commitment to the alliance.
NATO's sense of purpose took a boost after the annexation of the Crimean peninsula byRussiain 2014, fuelling fears among easternNATOmembers.
The alliance has since significantly strengthened its presence in EasternEuropeand built the capability for rapiddeploymentof troops in the event of conflict.
Stoltenberg underlined thatNATOmembers Lithuania, Estonia, and Latvia celebrated their 30th anniversary of independence this year, referring to the three Baltic states' split from the Soviet Union.
Portions of "DefenderEurope" were to be held in the three countries.
"Russiahas every right to feel safe within its borders, but so do our member states," said Stoltenberg.
ANATOofficial said there was nothing to be read into the fact that the exercise was taking place during 75th-anniversary celebrations in Moscow ofRussia's victory over Nazi Germany on May 9th.
"The exercise will take place from February to June," an official said. "This is the time when many military exercises are held each year."
"We recognise the critical role played by the Soviet Union in the victory over Nazi Germany."
Stoltenberg pointed out that the US had informedRussiaand the other members of the Organization for Security and Cooperation inEurope(OSCE) about the exercise in accordance with the guidelines on such matters.