UNITED NATIONS (Reuters) - The United States on Tuesday threatened to impose further targeted unilateral sanctions on anyone who hinders Democratic Republic of Congo’s already delayed preparations for an election to replace President Joseph Kabila.

The country’s election commission president said on Sunday that the vote, originally due in November 2016, was unlikely to take place in 2017, because of delays in registering millions of voters.

Further delays could trigger additional unrest following anti-government street protests last year in which security forces killed dozens of demonstrators. The opposition quickly denounced Sunday’s announcement as a declaration of “war”.

“We are ready to take additional action to sanction those who stand in the way of DRC’s first democratic transition of power,” U.S. Deputy Ambassador to the United Nations Michele Sison told the U.N. Security Council.

The United States imposed sanctions on several Congolese officials last year - blocking any financial assets in the United States and generally barring Americans from engaging in financial transactions with them - for hindering democracy.

“The Security Council should also consider targeted sanctions to reduce the violence in the DRC and help pressure all stakeholders to play a more constructive role in moving the country forward,” Sison said.

Kabila has refused to step down at the end of his second elected term in December, sparking protests that killed dozens of people. Militia violence has also intensified across Congo, raising fears the country will slide back into the wars at the turn of the century that killed millions.

The IMF has told Congo that “a credible path toward political stability” will probably be a condition of any assistance package, a letter seen by Reuters showed on Tuesday.

Under an accord struck on Dec. 31 between Kabila’s representatives and opposition leaders, Kabila, in power since 2001, is barred from trying to change the constitution to stand for a third term.

About 80,000 people have fled fighting between the Congolese army and a new rebel coalition, the United Nations said on Tuesday. Conflict has forced more than 1.5 million Congolese to flee their homes this year, while more than 3,000 have died since last October in central Congo’s Kasai region.