Deforestation in Brazil's Amazon region rose 28 percent over the past year, Environment Minister Izabella Teixeira said Thursday, announcing she was calling an emergency meeting to try to remedy the situation.

"We confirm a 28-percent increase in the rate of deforestation, reaching 5,843 square kilometers (2256 square miles)," Teixeira told a press conference, citing provisional statistics for August 2012 through July this year.

Extensive farming and soybean production in the northern state of Para and the central western state of Mato Grosso were key factors behind the rise, said Teixeira, citing increases for the two states of 37 and 52 percent respectively.

Teixeira said she would meet with Amazon regional environment secretaries of state next week to demand explanations and measures to deal with the situation on her return from a UN climate change summit in Warsaw.

She also criticized the apparent ineffectiveness of monitoring by federal state authorities.

"The Brazilian government does not tolerate and does not accept any rise in illegal deforestation," the minister said, insisting Brasilia is firmly committed to drastically reducing deforestation.

Although large in percentage terms, the rise in absolute terms is the second smallest in recent years as 2012 saw 4,571 square kilometers of deforestation, following an even more disturbing 6,418 square kilometers in 2011.

The worst year on record was 2004, when 27,000 square kilometers of forest was lost.

Global agricultural production giant Brazil is caught between environmental pressures and the interests of large-scale farmers.

The country's forestry code requires landowners in the Amazon to devote 80 percent to native forests. But enforcement has been lax.