OTTAWA - Travellers from Mexico and the Czech Republic will require visas to get into Canada, effective this week - a move that earned swift rebukes from both countries.

Immigration Minister Jason Kenney announced the measures Monday in separate news releases.

Canada lifted a visa requirement on the Czech Republic in October 2007. Since then nearly 3,000 Czech nationals have made refugee claims, compared with less than five in 2006, many of them Roma claiming discrimination at home.

"In addition to creating significant delays and spiralling new costs in our refugee program, the sheer volume of these claims is undermining our ability to help people fleeing real persecution," Kenney said in a release.

"All too often, people who really need Canada's protection find themselves in a long line, waiting for months and sometimes years to have their claims heard. This is unacceptable."

Refugee claims from Mexico have almost tripled since 2005, making it the No. 1 source country for claims for refugee status in Canada.

Over the first two days of the restriction, people travelling to Canada from either country can apply for entry on arrival at a border crossing. But beginning Thursday, a visa will be required.

Kenney said more than half the claims made by people from the Czech Republic are abandoned or withdrawn before a final decision is made on their status, an indication that many may be making false claims.

And he said only 11 per cent of Mexican claims processed by the Immigration and Refugee Board in 2008 were accepted.

Czech Foreign Minister Jan Kohout said the action was unprecedented against a European Union member and a war ally in Afghanistan.

He indicated to the Associated Press that the Czechs are likely to impose visas on Canadians travelling to the country.

Canada's embassy in Prague says 653 refugee claims were made in the first quarter this year. Human-rights organizations have repeatedly accused the country of discriminating against its 250,000 Roma minority.

The measure also drew fire from Mexico City.

"The government of Mexico regrets the decision by the government of Canada, announced today, to impose visas on Mexican nationals travelling to Canada as tourists," said a release issued late Monday.

"During the past few months Mexico has held consultations with Canadian authorities to assess other measures to deal with the problem of fraudulent claims.

"Furthermore, Mexico will continue to promote actions toward modifying the Canadian measure as soon as possible."