Ukraine's president has signed into law a controversial bill that makes Ukrainian the required language of study in state schools from the fifth grade on.
Petro Poroshenko signed the measure on September 25 after days of criticism, particularly from Ukraine’s ethnic minorities.
The bill does not outlaw instruction in other languages; students can still learn their native languages as a separate subject.
But that hasn’t assuaged the fears of groups such as Poles, Romanians, and Hungarians, all of which have sizable ethnic communities in Ukraine.
Russia has been particularly vociferous in its criticism, with the Foreign Ministry asserted this month that the law was designed to "forcefully establish a mono-ethnic language regime in a multinational state."
Poroshenko in signing the bill insisted that it "is in harmony with European standards and is an example for neighboring countries," according to a statement on the presidential website.
"The law raises the role of Ukrainian as a state language in the education process," he said. "The law ensures equal opportunities for all...It guarantees every graduate strong language skills essential for a successful career in Ukraine."
Language has become a hot-button issue across the country, particularly in eastern regions where the majority of the population speaks Russian as its first language.
The bill's language requirement overturns a 2012 law passed under Moscow-friendly President Viktor Yanukovych, who fled to Russia two years later amid mass street protests.
That legislation allowed for minorities to introduce their languages in regions where they represented more than 10 percent of the population.