A Kurdish Syrian refugee waits for transport during a sand storm on the Turkish-Syrian border near the southeastern town of Suruc in Sanliurfa province, Sept. 24, 2014. Reuters/Murad Sezer

The burden of the global refugee crisis is being unfairly shared, with just 10 countries hosting the majority of refugees, humanitarian groups said, urging wealthy nations to step up their response.

Fighting in Syria, Afghanistan, Burundi and South Sudan has pushed the total number of refugees to a record 21.3 million in 2016, according to the U.N. refugee agency UNHCR.

Fifty eight percent of refugees recognized by UNHCR have found shelter in one of only 10 neighboring countries: Jordan, Lebanon, Turkey, Pakistan, Iran, Chad, Ethiopia, Kenya, Uganda and the Democratic Republic of Congo.

"The responsibility of protecting refugees is very unequally distributed," UNHCR spokesman William Spindler told the Thomson Reuters Foundation in a statement on Monday.

In a report published on Tuesday, rights group Amnesty International said the unequal sharing was exacerbating the crisis as the main host countries, most of them poor, were unable to provide adequately for all refugees, pushing many to embark on perilous journeys to Europe and Australia.

"Children are not getting education, people are not getting sufficient, adequate food," Audrey Gaughran, Amnesty's director for global issues, said in a phone interview, describing the current situation as "unfair and unsustainable".

Amnesty called on developed nations to take in more refugees, according to their ability to shoulder the burden.

"The problem is not the global number of refugees, it is that many of the world's wealthiest nations host the fewest and do the least," Amnesty's secretary general Salil Shetty said in a statement.

"If every one of the wealthiest countries in the world were to take in refugees in proportion to their size, wealth and unemployment rate, finding a home for more of the world's refugees would be an eminently solvable challenge," he added.