The US State Department said Monday that Ukraine's local elections are "an important step" as the country continues to move forward with "difficult reforms to decentralize political power."

"We congratulate the people of Ukraine for exercising their right to vote in yesterday's local elections," State Department spokesman John Kirby said in a press statement.

On Sunday, Ukrainians cast their votes to elect mayors and members of regional councils in the sixth local elections held in the country since its independence in 1991.

The elections are not held in the areas in Donetsk and Lugansk regions, controlled by independence-seeking insurgents, and the government-supervised territories near the frontline of the recent fighting.

The voting was monitored by 1,554 international observers from 14 countries and 14 foreign organizations registered to supervise the process.

"We look forward to a successful second round of the elections on Nov. 15 for those mayoral races in which a single candidate did not receive a majority of the votes," Kirby said.

"We also hope the citizens living in the conflict zone, internally displaced persons, and refugees will soon have the opportunity to exercise their right to choose their leaders, in compliance with Ukrainian law, OSCE (Organization for Security and Cooperation in Europe) standards and as called for in the Minsk agreements," Kirby said.

The OSCE said Monday that Sunday's local elections in Ukraine were generally in line with democratic standards, but there was still room for improvement.