The U.N. envoy for international migration said Tuesday she's "very disappointed" that some countries are reneging on their support for a global compact to promote safe and orderly migration and reduce human smuggling and trafficking — some for "bizarre" reasons.

Louise Arbour said in an interview with The Associated Press that it's also "puzzling" because the global compact is not legally binding and after its formal adoption next month "there is not a single country that is obligated to do anything that it doesn't want to."

In July, 192 countries unanimously agreed on the first global document to tackle migration after lengthy negotiations on the often contentious issue, with only the United States boycotting.

But in recent months, countries including Hungary, Austria, Israel, Poland, Switzerland and Australia have dropped their support and said they won't attend the meeting in Marrakech, Morocco on Dec. 10-11 to formally approve the compact. And reservations have also been expressed in other countries such as Bulgaria, the Czech Republic and Slovakia.

Arbour said countries now having "second thoughts or misgivings" about the compact negotiated for six months in New York had "extracted concessions from others." Destination countries for migrants, for example, pushed very hard for the return home of migrants if they're no longer legitimately in a foreign country, she said.

The former Canadian judge and U.N. human rights commissioner, who will be secretary-general of the Marrakech meeting, said the backtracking on the agreement shows a "disconnect" in some countries between their foreign policies "and some domestic pressures or national concerns that obviously were not being fed into the process."

"Many of them have expressed it, in frankly, rather bizarre terms," Arbour said. "Some have said, for instance, we will not sign which is rather strange because there's nothing to sign. It's not a treaty. Others have said we will not come. Others have said we don't endorse the compact."

Nonetheless, Arbour said "we expect a very large participation, an overwhelming participation of U.N. member states" to formally adopt the compact by consensus. But she said she didn't know the number of countries that will attend the meeting, or how many world leaders, though there will definitely be some.

Arbour said that unfortunately "migrant" has been a bad word for a long time, "and it's extremely misunderstood."

She cited "the unbelievable confusion" between refugees who flee conflict or political persecution and are granted asylum in another country, and migrants "who overwhelmingly follow legal channels to access a country" by obtaining tourist, student or work visas, either for a short term or on a path to citizenship.

In the year 2000, 2.7 percent of the world's population were international migrants and "today it's 3.4 percent" — and 48 percent of them are women, Arbour said. That means today some 258 million people have left their home country either temporarily or permanently and settled in another country.

The remittances migrants send home — about 15 percent of their earnings — "represents three times the amount of total official development aid that rich countries send to the developing world," Arbour said.

She lamented that people overestimate the number of migrants in their countries, and their level of criminality and unemployment, "when the reality is completely different."

Arbour strongly refuted the demonization of migrants, and use of the term "illegal migrants."

"A lot of people who find themselves in an irregular situation in a country have actually entered perfectly legally," she said, but end up with sometimes serious and sometimes very minor issues regarding legal requirements to remain.

Arbour was critical of U.S. President Donald Trump repeatedly railing against migrant caravans from Central America as dangerous groups with criminals, and deploying troops to the U.S.-Mexico border.

"It's very difficult to counter a voice that occupies so much space in the media and in public opinion, even when on many aspects it's either very misguided or expresses concerns that are disproportionate regarding the reality of it," she said.

"What's happening at the southern U.S. border is what it is — 5,000, 7,000, 10,000 people seeking entry in a country of 330 million," Arbour said. "The global compact is about the mobility of hundreds of millions of people — many of whom have settled through legal channels in communities. So this is a wrinkle. There are wrinkles in different parts of the system."

The global compact recognizes that migration policies are a matter of state sovereignty, for every country to decide, she said.

As for countering the bad image of migrants, Arbour said, "it's not a question of trying to completely dismiss the very legitimate concerns that governments have, and that people have about controlling their borders."

She said the global compact is also about producing and promoting "a much, much more accurate perception of reality, so that national governments can have policies that make sense."

Arbour said the compact calls on countries to share migration data and "to push back on the drivers of migration — especially irregular migration" including conflict, poverty and lack of development and climate change. It also focuses on the development of skilled workers, who are needed in richer countries with low population growth, she said.