Kazakhstan, Sweden, Bolivia and Ethiopia were elected on June 28 to serve a two-year stint on the UN Security Council, with the Netherlands and Italy sharing the remaining spot.
Five non-permanent seats were up for grabs in the vote by the UN General Assembly, three of which were filled in a first round of secret ballot voting.
Kazakhstan beat out Thailand in a second round, picking up 138 votes against 55 for Thailand and winning a council seat for the first time since its independence from the Soviet Union in 1991.
Among the world's top aid donors, Sweden garnered 134 votes, scoring an outright win.
The Netherlands and Italy failed during three rounds to pick up the required majority and a new vote for the second seat reserved to western Europe was scheduled for 1900 GMT. Eventually the UN elected Italy to the Security Council under a deal that will see the Netherlands take over the seat in a year.
Applause rang out at the assembly hall after Sweden's victory was announced.
Swedish Foreign Minister Margot Wallstrom said she was "happy and proud" to see her country join the UN's top table, pledging to focus firmly on conflict resolution.
"With 40 conflicts and 11 full-blown wars, it is a very, very worrisome world that we have to take into account," Wallstrom said.
Italy has lobbied fiercely for a council seat, portraying itself as a crossroads country in the Mediterranean and touting its experience dealing with the refugee crisis.
The European country is also seen as a player in efforts to pull Libya out of chaos.
The Netherlands, home to the International Criminal Court and other world tribunals, has played up its commitment to international justice.
A first for Kazakhstan
Kazakh Foreign Minister Yerlan Idrissov said "we are very proud to be the first Central Asian country to serve on the council" and pledged to focus on nuclear non-proliferation and development.
Close to Russia, Kazakhstan gave up its nuclear arsenal after the breakup of the Soviet Union.
The newly-elected countries will take their place alongside the five permanent council members -- Britain, France, China, Russia and the United States.
The other five non-permanent members are: Egypt, Japan, Senegal, Ukraine and Uruguay.
The new members will begin their stint on January 1, just as the next secretary-general takes the helm following an October election to replace Ban Ki-moon.
Running unopposed as the candidate from Africa, Ethiopia picked up 185 votes.
With some 8,100 troops deployed in UN missions, Ethiopia is the largest contributor of UN peacekeepers and has been active in trying to mediate an end the war in South Sudan.
Bolivia, which had the backing of Latin American and Caribbean countries, won 183 votes.
The vote for a seat at the top diplomatic table caps years of lobbying by contenders.
As the ballot got underway, delegates at the 193-nation General Assembly were handed gift bags with miniature tulips and wooden shoes from the Netherlands, Baci chocolates from Italy and a buddha figurine from Thailand.