The ruling Social Democratic Party in Sweden decided on Sunday that the country should apply for NATO membership.
At the meeting held by the Social Democratic Party administration, the decision was made to apply for membership in the alliance.
"According to the decision of the party meeting on May 15, we support the application for NATO membership," the party said in a statement.
Prime Minister Magdalena Andersson said this would be the best decision for Sweden's security.
Foreign Minister Ann Linde described her party's move as a "historical decision" in a post on Twitter.
"Today the Swedish Social Democratic Party took a historic decision to say yes to apply for a membership in the NATO defence alliance. The Russian invasion of Ukraine has deteriorated the security situation for Sweden and Europe as a whole," she said.
After the decision is discussed in parliament on Monday, Sweden and Finland are expected to formally apply together for membership by Wednesday at the latest.