International tourist arrivals exceeded one billion for the first time last year despite ongoing global economic uncertainty and numbers will rise further in 2013, a UN body said on Tuesday.

The number of arrivals grew by 4.0 percent to 1.035 billion in 2012, up from 996 million in 2011, the Madrid-based United Nations World Tourism Organisation said in an annual survey.

"2012 was a year of constant economic instability in the entire world, especially in the euro zone. Despite this international tourism managed to maintain its course," the body's Secretary General Taleb Rifai told a news conference.

"We had a very good last quarter, much better than expected," he added.

The Asia-Pacific region posted the largest growth in visitor arrivals last year with the number up by 15 million or 6.8 percent to 233 million.

Growth was highest in Southeast Asia, with the number of arrivals up by 8.7 percent over 2011.

The Asia-Pacific region benefited from a recovery in the number of foreign visitors to Japan last year following a drop in 2011 due to the tsunami and earthquake that devastated parts of the country, said Rifai.

The improvement in the Japanese economy, the world's third-largest, also contributed to the rise in visitor numbers in Asia, he added.

Europe, the most visited region in the world, saw international tourist arrivals climb 6.0 percent last year to 535 million.

"Europe did much better than expected at 3.0 percent which is excellent for a mature economy, especially knowing that more than half of all arrivals come to Europe," said Rifai.

The only region to report a decline in tourist numbers compared with 2011 was the Middle East with 5.0 percent fewer arrivals because of political instability in popular tourist spots such as Egypt and Syria.

But the drop in the number of visitors to the region was smaller than the decline of 7.0 posted in 2011.

"The picture is a little bit mixed with some countries like Egypt which are doing slightly better but not as well as 2010," said Rifai.

The organisation forecasts international tourist numbers will grow in 2013 although at a slightly lower rate of 3.0-4.0 percent.

Asia and Africa are expected to post the greatest growth in tourist numbers this year.

The agency predicts tourist arrivals will increase by 5.0-6.0 percent in the Asia-Pacific region this year and by 4.0-6.0 percent in Africa.

The Middle East will see the number of foreign visitors to the region rise by 0 and 5.0 percent this year while Europe will post growth of 2.0-3.0 percent.

Global tourism figures were hit hard by the 2008 global financial crisis, with the rise in international arrivals that year slowing to 2.1 percent after jumping 6.6 percent in the previous year.

Arrivals plunged by 3.9 percent in 2009, its worst performance in 60 years, as the outbreak of the swine flu virus contributed to cash-strapped consumers' decision to stay home.

But international tourism arrivals bounced back the following year, rising 6.6 percent in 2010 and by 5.0 percent in 2011 even though global economic crisis had not yet ended.

The forecast of continued growth in international tourist arrivals next year comes a week after the International Monetary Fund (IMF) predicted that the global economy will grow slightly less in 2013 than expected.

It projects global gross domestic product annual growth of 3.5 percent this year, a dip of 0.1 point from its October forecast owing largely to weakness in the euro zone, and 4.1 percent in 2014.

China's economy is expected to grow 8.2 percent, followed by India at 5.9 percent.

The UN World Tourism Organisation predicts international tourist arrivals will rise by an average of 3.8 percent each year between 2010 and 2020 and will reach 1.8 billion in 2030.