CARACAS, July 18 (Xinhua) -- The Venezuelan government on Tuesday said it has rejected U.S. pressure to cancel a constitutional initiative or face additional "economic sanctions."

"Obviously the U.S. government is used to humiliating other nations through its international relations and thinks it is going to get the subordination it is accustomed to," the Venezuelan Foreign Ministry said in a statement.

Venezuelan President Nicolas Maduro has called for a National Constituent Assembly (ACN) to review and possibly rewrite the constitution, in a bid to overcome the political crisis that has paralyzed the country.

Venezuelans are expected to elect the members of the ACN on July 30.

The conservative opposition, which has the support of the U.S. government, opposes the initiative, going so far as to organize an informal poll on Sunday to gauge support for the measure.

The next day, a White House statement from President Donald Trump warned that if the Maduro government "imposes its Constituent Assembly on July 30, the United States will take strong and swift economic actions."

The Venezuelan Foreign Ministry noted "it is not the first time we have denounced and confronted crazy threats such as those contained in this unusual document," and vowed to hold the vote as planned, despite this latest "brutal threat."

In a swipe at the indirect voting system of the United States, which filters citizens' votes through the so-called electoral college, the ministry highlighted that the constituent assembly "will be elected by the direct vote, universally and in secret, of all Venezuelans."

The anti-government protests organized by the opposition in Venezuela have killed more than 90 people since early April.