Budapest. Hungary’s parliament voted Monday to ratify Sweden's bid to join NATO, ending more than 18 months of delays that frustrated the alliance as it sought to expand in response to Russia's war in Ukraine.

The vote, which passed with 188 votes for and six against, was the culmination of months of wrangling by Hungary's allies to convince its nationalist government to lift its block on Sweden's membership. The government of Prime Minister Viktor Orbán submitted the protocols for approving Sweden's entry into NATO in July 2022, but the matter stalled in parliament over opposition by governing party lawmakers.

Hungary's decision paved the way for the second expansion of NATO's ranks in a year after both Sweden and Finland applied to join the alliance in May 2022 following Russia's full-scale invasion of Ukraine -- an assault that was purportedly intended to prevent further NATO expansion.

Unanimous support among NATO members is required to admit new countries, and Hungary was the last of the alliance’s 31 members to give its backing since Turkey ratified the request last month.

Swedish Prime Minister Ulf Kristersson said his country was “now leaving 200 years of neutrality and nonalignment behind us."

"It is a big step, we must take that seriously. But it is also a very natural step that we are taking. NATO membership means that we've found a new home within a large number of democracies which work together for peace and freedom," he told a news conference in Stockholm.

Orbán, a right-wing populist who has forged close ties with Russia, has said that criticism of Hungary's democracy by Swedish politicians soured relations between the two countries and led to reluctance among lawmakers in his Fidesz party.

But addressing lawmakers before the vote, Orbán said: “Sweden and Hungary’s military cooperation and Sweden’s NATO accession strengthen Hungary’s security.”

NATO Secretary-General Jens Stoltenberg told The Associated Press that the vote "makes NATO stronger, Sweden safer and all of us more secure.”

Stoltenberg said Sweden brings with it capable armed forces and a first-class defense industry, and it is spending at least 2 percent of national gross domestic product on defense, which is NATO’s target level.

The vote “also demonstrates that NATO’s door is open" and that Russian President Vladimir Putin "did not succeed in his attempt to close NATO’s door,” he said.

On Monday, Orbán criticized Hungary's European Union and NATO allies for pressuring his government in recent months to move forward on Sweden's request to be part of the alliance.

“Hungary is a sovereign country. It does not tolerate being dictated by others, whether it be the content of its decisions or their timing,” he said.

Last weekend, a bipartisan group of US senators visited Hungary and announced it would submit a joint resolution to Congress condemning Hungary’s alleged democratic backsliding and urging Orbán’s government to allow Sweden into NATO.

A presidential signature, which is needed to formally endorse the approval of Sweden’s NATO bid, was expected within a few days.

In the US, White House press secretary Karine Jean-Pierre urged the Hungarian government to quickly complete the process of bringing Sweden into the alliance.

“Having Sweden as a NATO ally will make the United States even safer,” she said, speaking aboard Air Force One as President Joe Biden flew to New York for an appearance.

Kristersson, Sweden’s prime minister, met last week with Orbán in Hungary’s capital, where they appeared to reach a decisive reconciliation after months of diplomatic tensions.

Following their meeting, the leaders announced the conclusion of a defense industry agreement that will include Hungary's purchase of four Swedish-made JAS 39 Gripen jets and the extension of a service contract for its existing Gripen fleet.

Orbán said the additional fighter jets “will significantly increase our military capabilities and further strengthen our role abroad” and will improve Hungary’s ability to participate in joint NATO operations.

“To be a member of NATO together with another country means we are ready to die for each other,” Orbán said. “A deal on defense and military capacities helps to reconstruct the trust between the two countries.”

Robert Dalsjö, a senior analyst with the Swedish Defense Research Agency, told the AP on Friday that Hungary’s decision to finally lift its opposition came only after Turkey and its president, Recep Tayyip Erdogan, voted in January to ratify Stockholm’s bid.

After becoming the last NATO holdout with the Turkish vote, Orbán had to show some results for his government’s delays, Dalsjö said.

“In hiding behind Erdogan’s back, Orban could play, do some pirouettes,” he said. “Then when Erdogan shifted, Orban wasn’t really prepared for adjusting his position, and he needed something to show that could legitimize his turnaround. And that turned out to be the Gripen deal.”