MANILA - The US State Department on Tuesday expressed concern on the guilty verdict on Rappler CEO Maria Ressa and former writer-researcher Reynaldo Santos over a cyber libel case.

"The United States is concerned by the trial court’s verdict against journalists Maria Ressa and Reynaldo Santos and calls for resolution of the case in a way that reinforces the US and Philippines’ long shared commitment to freedom of expression, including for members of the press," US State Department spokesperson Morgan Ortagus said in a statement.

"Free speech is the lifeblood of democracy," she added in a tweet.

• Rappler chief Maria Ressa found guilty of cyber libel

A Manila court on Monday sentenced Ressa and Santos to at least 6 months and up to 6 years in prison over a 2012 story that linked a businessman Wilfredo Keng to alleged illegal activities.

News website Rappler and Ressa are also facing charges of tax fraud, violation of the Securities Regulation Code and the Anti-Dummy Law among others.

Ressa is a dual citizen of the United States and the Philippines.

For the European Union, the guilty verdict casts doubts "over the respect for freedom of expression as well as for the rule of law in the Philippines."

"Freedom of opinion and expression, online and offline, are essential parts of any democracy worldwide. The European Union will always stand up for these fundamental rights," the EU said in a statement.

The EU also reiterated that the Philippines is a party to the International Covenant on Civil and Political Rights, in which the right to freedom of expression is enshrined in Article 19.

"We expect the Philippines, like all countries, to uphold its international human rights obligations and protect and promote fundamental freedoms," the EU added.