The United States Navy's command ship the USS Mount Whitney began a three day visit to Helsinki harbour on Wednesday.
The 189 metre-long craft is the first of two Blue Ridge-class amphibious command ships as well as a Nato command ship and its commanding officer is Cassidy Norman.
The host of the visit is Commander Ilja Hakanpää, who is also the Finnish Navy's chief of staff. Finland is not a member of Nato but joined the military alliance's Partnership for Peace in 1994 and entered a three-year agreement in 2017 to continue as an Enhanced Opportunity Partner.
The command vessel will not be open to the public while it is in port off the Helsinki district of Hernesaari and the visit is set to end on 6 July.
USS Mount Whitney served as a Nato command ship during the Libyan Civil War of 2011, when the military alliance prevented President Muammar Gaddafi's troops from attacking a rebel stronghold in Benghazi.
According to Estonian public broadcaster ERR, the Mount Whitney stopped at Muuga Harbour, the country's biggest cargo port, at the end of last month after it served as the command vessel during Nato Baltops 2019 exercises, in which Finland also participated. Estonia has been an active Nato member since 2004.