MADRID (AFP) - International tourism grew 4 per cent in the first half of this year, with Asia posting the strongest growth, the World Tourism Organisation said on Thursday (Sept 29).

At around 561 million, the number of international tourists surged 21 million between January and June compared to the same period a year earlier, the Madrid-based United Nations body said in a statement.

"Tourism has proven to be one of the most resilient economic sectors worldwide," UN World Tourism Organisation (UNWTO) Secretary-General Taleb Rifai said in the statement.

Tourist arrivals rose at the fastest rate in the Asia-Pacific region, where numbers were up by 9 per cent due to "robust intra-regional demand".

Africa, where an outbreak last year of Ebola in West Africa caused tourists to shun travel to the entire continent, posted a 5 per cent rise in international arrivals, with sub-Saharan African "recovering vigorously" with a 12 per cent increase.

In Europe, the world's most-visited region, tourist arrivals grew by 3 per cent.

Growth in western Europe was sluggish, up by just 1 per cent, while northern, central and eastern Europe each recorded 5 per cent more international arrivals.

International arrivals in the Americas were up 4 per cent in the first half of the year, in line with the global average.

People in China, the world's top source market for international tourists, spent 20 per cent more on international travel.

In the United States, the world's second largest market, the rise was 8 per cent, as the strong dollar made foreign travel cheaper.

In 2015, the number of international tourist arrivals grew by 4.4 per cent from the previous year, to 1.2 billion.

The UN body said it expects the figure will grow again by 4 per cent this year.