The number of annual tourists crossing international borders will reach 1 billion this week, the United Nations World Tourism Organisation said on Wednesday, with Chinese travelers the biggest growth driver.

Tourism grew between 3.5 per cent and 4 per cent in 2012, the secretary general of the UNWTO said, with the billionth tourist expected to touch down somewhere in the world on Thursday.

Chinese tourists, whose numbers increased 30 per cent year-on-year, and their Russian counterparts, whose numbers swelled 16 per cent, offer big opportunities for traditional tourist destinations like the Mediterranean, but countries must do more to make travelling easier for them, the UN said.

"It is not acceptable any more to spend so much money on promoting some destinations and then spend even more money to tell people not to come," the UN's Taleb Rifai said in an interview with Reuters.

Rifai said Mediterranean countries must relax visa restrictions for visitors from nations like Brazil, Russia, India and China, where growth has outpaced recession-hit Europe and emerging middle classes are increasingly travelling outside national borders.

"We need to be specially tailoring and designing policies. A Chinese is not going to come to the Mediterranean just to visit one destination... These are the travelers of the future."

He also warned against tax hikes that could scare away tourists.

Many European countries have raised taxes as part of austerity programmes to get government finances back on track. When Spain raised valued added tax (VAT) for the leisure sector to 10 per cent from 8 per cent this year, the industry estimated it could lose around 2 billion euros ($2.6 billion) in revenue.

"We need to be sure that these taxes are designed in policy and in practice so that they do not choke the industry and in layman's terms, kill the goose that lays the egg," he said.

Spain, where tourism accounts for 11 per cent of economic output, and its highly indebted euro zone peer Greece, did not fare as well from unrest in the Middle East this year as last.

Visitors shunned North Africa last year as Arab Spring protests spread across the region, redirecting up to 7.5 million tourists to sunny Mediterranean destinations like Spain, Greece and the Balkans.

Tourism to Spain grew 3 per cent this year, compared to 8 per cent in 2011 when unrest in Arab countries was flaring up.

The UNWTO, which is based in Madrid, expects the number of world travellers to reach 1.8 billion by 2020, when one in 10 people will be employed in the travel and tourism industry. – Reuters