The Danish Royal army has deployed some 150 troops and equipment to Tapa, Estonia.
The troops -- part of the Viking Company, a segment of the Jutland Dragoon Regiment -- are formally replacing the French 5e Dragons Regiment as the additional element in NATO's Enhanced Forward Presence battlegroup in Tapa.
The vehicles include Piranha vehicles, trucks and sanitary vehicles.
NATO's Enhanced Forward Presence is currently led by the UK Royal Tank Regiment, with France and Denmark also providing forces on a rotating basis.
Baltic leaders have called for NATO troops to be stationed at bases such as Tapa on a permanent basis.
“The Bear, as Russia is called, is always next door. The population still remembers how life was like in Soviet times, and definitely, they do not want to go back -- including the ethnic Russian-Estonian population, who declare themselves Estonians and don`t want to have anything to do with Putin`s Russia," says Joao Espinho, an aviation advisor at Amari Airbase in Estonia.
"Estonia is a NATO member, it is an EU member. Putin would have to think twice before invading."
In addition to the 150 troops in Estonia, Denmark plans to send two fighter jets to an island in the Baltic Sea as well as a combat battalion of 700 to 800 soldiers to contribute to NATO's operations.
NATO Secretary-General Jens Stoltenberg has repeatedly warned that the military alliance will defend every inch of its territory should Russia attack a member country.
"NATO is the strongest alliance in history, and make no mistake: we will defend every ally against any attack on every inch of NATO territory," Stoltenberg said at the organisation's headquarters in Brussels on Thursday. "An attack on one ally will trigger a response from the whole alliance."
While some of NATO's 30 member countries are supplying arms, ammunition and other equipment to Ukraine, NATO as an organisation is not.
However, Estonia, Latvia and Lithuania said in a joint statement: "We would need to urgently provide Ukrainian people with weapons, ammunition and any other kind of military support to defend itself as well as economic, financial and political assistance and support, humanitarian aid."
The Pentagon has also put up to 8,500 US troops on heightened alert, so they will be prepared to deploy if needed to reassure other allies.