Swedish Defence Minister Peter Hultqvist said on Friday that an armed attack against his country cannot be ruled out.
He told Deutsche Welle that he wants to make it clear that Sweden is ready to defend itself. "Sweden is ready to defend its sovereignty and integrity, also together with other countries that we have cooperated with over many, many years," Hultqvist stressed.
During the past weeks, Sweden has increased its presence in Gotland, its largest Baltic Sea island, in view of Russian activities in the area, as tensions surrounding Ukraine continue to run high.
Officials said this was not a higher level of emergency, however, but a redistribution of resources on call.
The army published pictures of the troops and additional equipment on Thursday.
Hultqvist visited the soldiers in Gotland on Wednesday. He pointed out that the operation, a show of Swedish sovereignty, would not be completed within a week. "We must remain tenacious," he said.
Hultqvist has recently said that European security as a whole is "being challenged and threatened by Russia's unacceptable actions."
A few days ago, Russian landing ships were observed in the Baltic Sea. A total of six ships were seen in the area, more than usual, according to the TT news agency.
NATO close 'partner'
They have since left the Baltic Sea, but three were anchored in the Kattegat in the middle of the week during poor weather conditions.
Sweden, like neighbouring Finland, is not a NATO member, but both countries are close partners of the military alliance. In Finland, the question of NATO membership is regularly debated.
Meanwhile a large Russian cargo plane made a lengthy detour through Finnish airspace last weekend, according to the Finnish radio station Yle.
NATO Secretary General Jens Stoltenberg is set to meet Sweden's Foreign Minister Ann Linde and Finland's Foreign Minister Pekka Haavisto on Monday.
