Canada is rejecting more refugee claims from people who crossed the border illegally as Prime Minister Justin Trudeau’s government seeks to dissuade, block and turn back thousands more, according to new data obtained by Reuters.

Nigeria is one of the most affected countries by the new Canadian policy of shutting its doors to persons suspected to be lying with asylum alibi. To make good its decision, Canada has sent its immigration and refugee minister to Nigeria, asking the Nigerian government to help discourage its citizens from crossing illegally into Canada to claim refugee status and asking the United States to not grant visas to people who might then go to Canada.

Forty percent of such border crossers whose claims were finalised in the first three months of this year were granted refugee status, down from 53 percent for all of 2017, according to data provided by Canada’s Immigration and Refugee Board. There were no claims finalised in the first three months of 2017.

The wave of illegal border crossings started up in January 2017 and ramped up over the summer as many Haitian immigrants in the United States who were at risk of losing their temporary legal status streamed into Canada on expectations that they could find a safe haven. In the months since, thousands of Nigerians have made the same crossing.

More than 27,000 asylum seekers have walked across the Canada-U.S. border since President Donald Trump took office, some of whom have told Reuters they left the United States because of Trump’s policies and rhetoric towards immigrants.

The influx has strained Canada’s backlogged system for assisting people seeking refugee status, leaving aid agencies scrambling to meet growing demand for housing and social services.

A U.S.-Canadian border pact that turns back asylum seekers at border crossings allows immigrants who cross illegally into Canada outside of an official border crossing to apply for refugee status.

Trudeau’s government has sought to stem the influx by sending officials to the United States to dissuade Haitians, Salvadorans and others from illegally entering into Canada to seek refugee status. It has asked the United States to amend an agreement between the two nations to make it easier to turn back thousands of illegal border crossers.

Like Haitians, thousands of immigrants from El Salvador in the United States have been told that they will lose their temporary legal status.

Immigration and Refugee Board data shows that while only a small number of border-crosser claims have been processed, acceptance rates are down for all groups seeking refugee status. The success rate is especially low for two of the biggest groups of asylum seekers to enter the country illegally: Haitians and Nigerians, with overall acceptance rates of 9 percent and 33.5 percent, respectively.