Image copyright Getty Images

The UN World Tourism Organisation says tourism spending has outpaced global trade for the fourth year in a row.

The US followed by China are the world's most popular destinations, followed by France and Spain.

According to the UNWTO's figures, released earlier this month, international tourism grew by 4% in 2015 generating $1.4trn ($966bn).

In comparison, global trade increased by just 2.8% in 2015 according to the World Trade Organisation.

"Tourism is today a major category of international trade in services," said UNWTO Secretary-General Taleb Rifa.

In 2015, tourism accounted for 7% of the world's total exports up from 6% in the previous year.

Tourism spending, which includes accommodation, food, entertainment, and services, has helped to offset drops in exports that have occurred as commodity prices have fallen.

"Tourism has shown a strong capacity to compensate for weaker export revenue in many commodity and oil-exporting countries," said Mr. Rifai. "Tourism is increasingly an essential component of export diversification for many emerging economies as well as several advanced ones."

Falling commodity prices have lowered the overall value of imports for many countries. According to the CPB Netherlands Bureau of Economic Policy Analysis, 2015 was the worst year for world trade since 2009.

Top travellers

The increase in international tourism came even as attacks at transportation hubs and on airlines raised concerns about travellers' safety.

The US and China, along with the UK were the leading sources for outbound travellers.

The number of outbound tourist from China has risen every year since 2004 with their spending increasing by 25% last year.