The United Nations Sunday marks International Migrants Day, to commemorate the contributions of hundreds of millions of migrants who have faced challenges to leave home for a better life. 

This year’s celebrations occur as increasing numbers of European countries close their doors to refugees and economic migrants from Afghanistan, the Middle East, and Africa. They are taking place as a growing number of migrants from Central America try to cross the southern U.S. border.

The United Nations says people do not willingly leave home. It says most of the world’s 280 million international migrants have been forced to move by conflict, persecution, desperate poverty, and, increasingly, climate change.

Many migrants, who lack legal pathways, take dangerous routes to countries of asylum. Many are exploited, abused, and die along the way. The International Organization for Migration estimates more than 50,000 migrants have died, and thousands more have disappeared over the past eight years.

IOM Director-General Antonio Vitorino says the world is failing to protect the most vulnerable people.

“Indeed, the world over, migrants move, often at great risks, for the most fundamental of reasons — to seek a better future for themselves and their families. Behind every journey there is a person, there is a story no less valid than our own. This year to mark International Migrants Day, I want to pay tribute to all those who have died or disappeared on the threshold of their dreams.”

World Health Organization Director-General Tedros Adhanom Ghebreyesus echoes these sentiments. He says countries have a legal and moral duty to assist those in distress and provide health services and protection for vulnerable people.

“In seeking a better life, many migrants are in vulnerable situations, suffer from poor health and cannot access health services. We can prevent suffering and save lives by supporting countries to build resilient health and care systems that are sensitive to the needs of migrants,” he said.

The United Nations says migrants’ rights are human rights and must be respected without discrimination. These rights, it adds, pertain regardless of whether people are forced to flee or move voluntarily.