President Trump heaped new praise Friday on Canada’s immigration system, which has served as a model for countries around the world because it focuses more on immigrants who can contribute to the economy than those with little more than family ties.

Trump sent out a Tweet after apparently watching a segment on Fox & Friends that featured Nick Adams, a conservative author who the book Green Card Warrior: My Quest for Legal Immigration in an Illegals’ System.

During the segment, Adams spoke against “multi-culturalism” and immigrants who enter the country to “milk us,” which drew a salute from Trump who described Adams’ book as a “must read.”

“The merit-based system is the way to go. Canada, Australia!” he wrote.

That tweet followed Trump’s comments during his joint address to Congress on Tuesday, when he praised the system used by Canada, Australia and many other nations during a portion of his speech that called for reforming an “outdated” legal immigration system that hurts American workers.

“Switching away from this current system of lower-skilled immigration, and instead adopting a merit-based system, will have many benefits,” Trump said. “It will save countless dollars, raise workers’ wages, and help struggling families — including immigrant families — enter the middle class.”

Canada has long used immigration as a way to drive its economic engine, and limits the relatives Canadian citizens can bring in.

About 63% of those granted legal permanent residence in Canada — the final step before becoming citizens — are admitted for their economic skills, with only 24% admitted based on having family members living in the country. The U.S. system is reversed: 63% of green cards are given to immigrants with family connections, and only 13% given based on economic reasons.

Canada was also the first country to use a point system to grade economic immigrants — a 100-point scale introduced in the 1960s that rewards foreigners with PhDs and extensive work experience in specialized fields. It became increasingly popular in the 2000s, as countries that included Australia, Denmark, Japan and the United Kingdom adopted versions of it.

“It was very trendy,” said Meghan Benton, a senior policy analyst at the non-partisan Migration Policy Institute.

Applicants are given a score on a 100-point scale, with points awarded in six categories:

• 28 maximum points for language skills. The more fluent they are in English and French, Canada’s two official languages, the more points they get.

• 25 points for education — 5 for a high school diploma, 19 for a two-year college degree, 25 for a PhD.

• 15 maximum points for work experience — the more skilled the job, and the more years spent doing it, the more points.

• 12 maximum points for age — the younger the applicant, the more points awarded.

• 10 points maximum if they have a current job offer from a Canadian employer.

• 10 points maximum for “adaptability,” which includes things like family ties to Canadians or past visits to the country.

Those who score 67 points or higher are eligible to immigrate. Immediate relatives of Canadian citizens do not go through the grading process.

Benton said the formula has changed over the years, as Canada has recently put more emphasis on foreigners with standing job offers. Canada and others countries, she said, realized that simply admitting people with PhDs wasn’t an economic cure-all, since many couldn’t find jobs in their fields and were forced to do work far below their education levels.

“You had scientists working as taxi drivers,” she said. “Classic brain waste.”

The country also made a major revision in 2015, when it allowed Canadian provinces to sponsor immigrants based on labor shortages. The goal was to tie the system more closely to local demands.

The question in the U.S. now is how much Trump wants to emulate Canada’s system. “We’ve been discussing here exactly what he means,” Benton said.

Roy Beck, president of NumbersUSA, a group that advocates for lower levels of immigration, interpreted Trump’s comments as a call to shift away from an immigration system that places such a high priority on family-linked migration — allowing U.S. citizens to sponsor not just spouses and children, but also extended family members.

Beck said the U.S. also allows in too many refugees and foreigners chosen through the diversity visa program, which allows 50,000 people to enter the U.S. each year from under-represented countries, mostly from Africa, Asia and Eastern Europe. That amounts to less than 5% of the 1.2 million immigrants admitted to the U.S. in 2015.

“He’s very clearly saying we should stop importing poverty,” Beck said. “He didn’t use that term. But he’s saying that we’re going to stop bringing in people who do not meet some criteria of merit.”

Clarissa Martínez-de-Castro, deputy vice president of the National Council of La Raza, a group that advocates for immigrants in the U.S., said Trump was clearly embracing a proposal by Sen. Tom Cotton, R-Ark., to cut all legal immigration in half. She said Cotton’s proposal, and Trump’s apparent embrace of that model, show what their true end goal is.

“Many Republicans have been trying to hide behind this veneer of, ‘We’re not against all immigrants, we’re just concerned with illegal immigration,'” Martínez-de-Castro said. “They’re trying to eviscerate all of it.”