Russian Defence Minister Sergei Shoigu on July 24 said that NATO received "unhindered access" to Sweden and Finland's airspace and territorial waters in exchange for allowing the two nations to "fully participate" in the alliance's military exercises, according to the TASS state news agency.

"What is described by the Russian defence minister is false. NATO does not have unlimited access to Finnish and Swedish territorial waters and airspace," Sweden's Defence Minister Peter Hultqvist told Swedish Radio on Friday, echoing similar comments by Finland's defence ministry last week.

"A special permission is required for any state-owned ship and aircraft to enter our territory," Hultqvist added.

Finland last week said Shoigu's comments had "a number of inaccuracies and factual errors", noting that the country "does not participate fully in NATO exercises".

Shoigu was referring to a trilateral statement of intent signed in May by Sweden, Finland and the United States. The document claims to be legally non-binding and aims "to support a stable and secure environment in the Baltic Sea region".

But Shoigu claimed it gives Stockholm and Helsinki "the possibility to use (NATO's) command systems for the control of troops and weapons".

"Such steps by our Western colleagues lead to the destruction of the existing world security system," Shoigu said.

Finland as well as Sweden denied his claims saying they do not have "full access to NATO's command-and-control system".

- Increased military activity -

Sweden and Finland -- the Nordic and Baltic region's only non-aligned countries -- have recently stepped up their military cooperation with the US.

The region has seen an increase in Russian military activity, including several airspace violations and war planes allegedly flying without their identifying transponders.

In recent years, concerns have risen about Russia's intentions in the region -- with alarms bells ringing after Moscow's annexation of the Crimean peninsula from Ukraine in 2014.

In June 2015, US think tank Cepa published a report claiming Russia had held exercises with 33,000 troops aimed at practising an invasion of Sweden's Baltic Sea island of Gotland, among other sites.

Sweden has resumed military activities on Gotland.

It also this year reintroduced compulsory military service, seven years after it was abolished.

The first group of 19 recruits were called in for military training on Monday, Swedish Radio reported, adding that 4,000 soldiers would be trained this year.