Romania's centrist president Klaus Iohannis has asked opposition Liberal Party leader Ludovic Orban to see if he can form a transitional government until a parliamentary election next year.

Prime Minister Viorica Dancila's center-left government collapsed this month after losing a no-confidence vote in parliament.

Orban, 56, who becomes prime minister-designate, must put together a cabinet and governing program which will need to win a vote of confidence in parliament.

Dancila, who remains interim premier until parliament endorses the new cabinet, is the third Social Democrat Party prime minister in as many years.

Lawmakers expected to endorse Orban's cabinet, but he may struggle to negotiate majorities for policy moves, given the fragmented opposition.

"The other parties will try a permanent blackmail, vote by vote, measure by measure," Sergiu Miscoiu, a political science professor at Romania's Babes-Bolyai University, said.

Orban said his government's chief objectives would include downsizing government structures, investment in key infrastructure projects and correcting economic measures, which have hit the business sector.

He also said focus will be given to "ensure real independence of the justice system."

The European Union and the US have criticized the previous government for watering down anti-corruption legislation.

The EU member state will hold a presidential vote in November, with local and parliamentary elections due to take place in mid to late 2020.