The US government imposed sanctions on a senior police official in the Democratic Republic of Congo on Thursday for his role in what it described as the violent suppression of opposition to President Joseph Kabila's government.

President Kabila is ineligible to stand in Congo's next election in November after serving two elected terms. Opponents accuse him of plotting to hold on to power by delaying the poll or changing the constitution to remove the term limit, as several African leaders have done.

The Treasury Department said Kabila's government has engaged in a pattern of repression, including the arrest of members of the opposition and violent suppression of political protests to avoid scheduling national elections.

The department put Celestin Kanyama, police commissioner in the Congolese capital, Kinshasa, on its list of "specially designated nationals" whose assets are blocked and are generally blocked from dealing with Americans.

Treasury accuses Mr Kanyama of responsibility for dozens of deaths and other actions that have created a "climate of fear" over the past three years.

These including raids during "Operation Likofi," commanded by Kanyama, in which uniformed police wearing black masks dragged suspects out of their homes at night at gunpoint, with no arrest warrants. At least 50 young men and boys were reportedly killed and more than 30 others reportedly vanished.

In January 2015, when Mr Kanyama was police commissioner, more than 40 people were killed during demonstrations in the capital city, including at least 20 fatally shot by security forces.

"Treasury's action today sends a clear message that the United States condemns the regime's violence and repressive actions, especially those of Céléstin Kanyama, which threaten the future of democracy for the people of the Democratic Republic of the Congo," said John Smith, acting director of the Office of Foreign Assets Control, said in a statement.

Mr Kanyama was not immediately reachable for comment. DR Congo's government has rejected accusations that police carried out summary executions during Operation Likofi or used excessive force during the 2015 protests.

DR Congo condemned Treasury's announcement, saying it would infringe upon its sovereignty and undermine bilateral relations.

"It will also embolden those who seek to divide our nation and impede our democratic processes," Barnabé Kikaya Bin Karubi, a diplomatic advisor to Mr Kabila, said in a statement.

Reuters reported this month that members of Congress and other US officials had been pushing for sanctions against members of Kabila's inner circle, but had run into opposition from European powers wary of moving too quickly.