President Vladimir Putin will consider a range of measures to bolster Russia's security if Finland or Sweden join NATO once the defence ministry presents him with its proposals on the subject, the Kremlin said on Thursday.

Speaking to reporters on a conference call, Kremlin spokesperson Dmitry Peskov said the ministry still needed time to put the proposals together.

Peskov's comments come after Dmitry Medvedev, one of Putin's closest allies, warned NATO that Russia would have to bolster its defences in the region if Finland and Sweden joined the U.S.-led military alliance.

(Reporting by Reuters)