CARACAS, Feb. 21, 2014 (Xinhua/ Sun) Venezuelan President Nicolas Maduro has called for direct talks with the United States, which has criticized his government for arresting protesters.

Meanwhile, opponents and supporters of the president have both prepared rallies in the capital Caracas on Saturday.

Friday, Venezuelan President Nicolas Maduro challenged his U.S. counterpart Barack Obama to hold a high-level dialogue between their governments. He also proposed to appoint an ambassador to Washington.

One day earlier, the U.S. president criticized Maduro's government for using force against protesters.

And four days ago, Venezuela expelled three more U.S. diplomats on charges of stirring up unrest.

While Maduro floats the idea of talks, tensions are climbing on the streets.

At least nine people have been killed and nearly 140 injured since the anti-government demonstrations erupted in Caracus on Feb. 12.

Over 100 have been arrested.

The situation is getting worse since a key opposition leader, Leopoldo Lopez, surrendered to police Tuesday. He's accused of inciting violence.

Many fear there might be more violence as both opponents and supporters of Maduro have vowed to stage massive rallies in Caracas on Saturday.