The council can authorise sanctions and the use of force in conflicts

Libya, Vietnam, Burkina Faso were elected to the UN's top body unopposed, in a UN general assembly secret ballot.

Croatia and Costa Rica won seats after their respective rivals, Czech Republic and Dominican Republic, withdrew.

Nations compete keenly for council membership. The five permanent members - France, Britain, China, the US and Russia - can veto any candidate.

We are back to the international community... all the problems we have faced in the past are now behind us Giadalla Ettalhi Libyan ambassador to the UN

The 10 non-permanent seats on the 15-member council are allocated according to regional groupings.

Five members are replaced every year, with each serving a two-year term.

Regional balance

Libya and Burkina Faso were endorsed by the African group and faced no opposition.

Vietnam ran unopposed, with endorsement from the Asian grouping.

Croatia and Costa Rica failed to secure a two-thirds majority of votes in the first two rounds of voting. They won their posts after their rivals pulled out in the third round.

NON-PERMANENT MEMBERS Belgium - until end of 2008 Indonesia - until end of 2008 Italy - until end of 2008 Panama - until end of 2008 South Africa - until end of 2008 Burkina Faso - until end of 2009 Libya - until end of 2009 Vietnam - until end of 2009 Costa Rica - until end of 2009 Croatia - until end of 2009 Profile: UN Security Council

Libya's ambassador to the UN, Giadalla Ettalhi, hailed the result as a special moment for his country:

"I think for us it has a very important meaning, being elected to the Security Council by a very high score," Mr Ettalhi said.

"It means, I can say, we are back to the international community, that all the problems we have faced in the past are now behind us."

The aim is to achieve a regional balance, with five Asian or African members, two from Latin America, one eastern European and two members from western Europe or other regions.

Last year's Latin America ballot lasted for more than three weeks, after an epic 47 rounds of voting failed to choose a winner between Venezuela and US-backed Guatemala. Panama was eventually selected as a compromise candidate.

Some countries announce their candidacy many years in advance and actively lobby for votes.

The council has the power to introduce sanctions regimes and authorise the use of force in conflicts.