Russian President Vladimir Putin has signed a new law expanding the definition of treason, a move critics say gives the government broad authority to brand anyone a traitor.

The law went into effect Wednesday — despite a promise by Mr. Putin on Monday that he would review the measure.

Previous legislation described high treason as espionage or other assistance to a foreign state that damages Russia's external security. The new law will also apply to Russian citizens working for international organizations and intelligence agencies.

The maximum sentence for anyone convicted of treason remains 20 years.

A former Constitutional Court judge told a presidential rights council meeting on Monday the new law is so broad that it does not require authorities to prove that a suspect has damaged state security.

Rights groups, including Human Rights Watch, and European Union foreign policy chief Catherine Ashton have expressed concern about possible misuse of the proposed law.

It follows the swift passage of a series of other Russian laws this year restricting civic freedoms and foreign influence. These include laws that criminalize slander, blacklist websites containing what officials consider objectionable material, tighten restrictions on nongovernmental groups with foreign funding, and curb public protests.

The Kremlin has consistently maintained that it is operating within the law and that the measures are meant to strengthen security and keep the public safe.

Critics say the new legislation is designed to suppress information and stifle dissent.