Here's a look at what exactly the Safe Third Country Agreement is, and why it's been challenged in court — again. 

U.S. President Donald Trump on Tuesday threatened retribution against Guatemala over immigration after the country's high court blocked its government from signing an asylum deal with the United States.

The organization says the policy no longer guarantees asylum seekers the same legal rights as those offered in Canada.

American officials are inching closer to allowing talks to amend the Safe Third Country Agreement with Canada.

'They are being dishonest,' Conservative immigration critic Michelle Rempel says of the government after memos show officials say the Safe Third Country Agreement is not working.

Coinciding with World Refugee Day, the event saw participants congregate outside Hussen's constituency office in Toronto. They called for an end to the Safe Third Country agreement with the United States.

"If there was ever a time for Canada to step up, the moment is now," MP Jenny Kwan implored.

As pressure for Canada to suspend the Safe Third Country Agreement grows, some are left wondering whether doing so would increase the flow of refugees into Canada.

Three advocacy groups are throwing their support behind a woman asking the Federal Court to strike down the agreement that results in most asylum claims made at land borders being denied.

The Prime Minister's Office said Justin Trudeau and Donald Trump spoke about the border but didn't say if they spoke about the influx of migrants heading into Canada.