Lithuania said Monday it plans to use EU funds to build a fence on the border with Russia's highly militarised Kaliningrad exclave to boost security and prevent smuggling.

Baltic states have repeatedly voiced their concern at the Russian military build-up in the exclave sandwiched between Poland and Lithuania, both EU and NATO members.

Construction of the 130-kilometre (80-mile) fence will start this spring and will be finished by the end of the year, Interior Minister Eimutis Misiunas told AFP.

"The reasons are both economic to prevent smuggling and geopolitical to strengthen the EU's external border," he said.

The two-metre (six-foot) high fence will cost around 30 million euros ($32 million) and will be mostly funded by the European Union.

"It would not stop tanks but it will be difficult to climb over," Misiunas said.

The stretch of border is currently a popular route used by Kaliningrad-based cigarette smugglers to ferry contraband into Lithuania.

Misiunas said the fence could prevent cross-border "provocations", recalling a 2014 incident in which Estonia accused Russia of abducting an intelligence officer at gunpoint on the border.

NATO is deploying troops in the Baltic states and Poland to deter Russia from making more land grabs following its 2014 annexation of Crimea from Ukraine.

The Kremlin denies any territorial ambitions and insists NATO is trying to encircle Russia.

Moscow's deployment of nuclear-capable Iskander missiles into Kaliningrad last year and frequent military drills in the Baltic region have rattled neighbouring Poland and Lithuania.

Over the next few months, the United States will also deploy part of an armoured brigade to Lithuania and other Baltic NATO states on a rotational basis.

Although no troop figures have been made public, Lithuanian authorities expect to host hundreds of US personnel for exercises with other NATO troops in the coming months.

Ordered by the outgoing Obama administration to reinforce NATO's vulnerable eastern flank, the brigade arrived in Poland last week as part of one of the largest deployments of US forces in Europe since the Cold War, an operation that Moscow angrily branded a security "threat".

The incoming administration of US President-elect Donald Trump has suggested it will seek to ease tensions with the Kremlin, but has not yet publicly addressed the issue of fresh US troop deployments near Russia's borders.

According to Poland's Defence Minister Antoni Macierewicz, a total of 7,000 US and NATO troops will be stationed in his country in the coming years.