After Iceland, Marco Rubio will depart for Athens to participate in a 'strategic dialogue' with Nato member Greece on regional and energy security. (EPA Images pic)

REYKJAVIK: US secretary of state Marco Rubio said Tuesday that Iceland had long been a "critical outpost" for security during a visit to the island, as his country pushes for greater US influence in the Arctic region.

His trip comes after US President Donald Trump has stirred up the power balance in the region by making threats to buy or annex Greenland.

The US signed a security pact with Denmark and Greenland in late September that will allow Washington to establish two new military bases there, drawing the autonomous Danish territory further into US orbit.