Sweden cleared a last hurdle towards NATO accession on Monday after Hungary's parliament approved membership of the traditionally neutral Nordic country.

Sweden and Finland both bid to join NATO after Russia sent tens of thousands of troops into Ukraine in 2022, setting off Europe's biggest conflict since the Second World War, an attritional battle that grinds on two years later.

"We will closely monitor what Sweden will do in the aggressive military bloc, how it will realise its membership in practice ... based on this, we will build our response with retaliatory steps of a military-technical and other nature," Maria Zakharova, a spokesperson for the Russian Foreign Ministry, said.

"Sweden's accession to NATO is accompanied by the ongoing fuelling of anti-Russian hysteria in the country, which, unfortunately, is encouraged by the Swedish political and military leadership, but its main source is abroad. It is not the Swedes themselves who are making the choice; this choice has been made for the Swedes," she said.

Sweden's move to join NATO was fuelling tensions and militarisation, she added.

Russia's embassy in Stockholm had also spoken of unspecified military and technical counter measures on its Telegram account on Tuesday depending on the extent of NATO troops and materiel deployments inside Sweden.

Swedish Prime Minister Ulf Kristersson said Russia's comments were not surprising and indicated his country was unfazed.

"That's what they said when Finland joined NATO," as well," news agency TT reported Kristersson as saying on Wednesday during a trip to the town of Trollhatten in southern Sweden.

"It is well known that Russia doesn't like the fact of either Sweden or Finland being NATO members, but we make our own decisions."

He said Sweden was "on its toes" to meet any response from Russia. "We are well prepared and we see what they are doing," he said.