Johannesburg, South Africa ? As the United Nations called for an end to days of deadly violence in Congo, Sen. Barack Obama canceled a long-scheduled trip to the Central African nation that has been roiled by fighting between followers of the country’s two presidential candidates.

The U.S. Embassy in Kinshasa, the Congo capital, asked Obama on Tuesday to suspend his visit in the wake of reports that 14 people had been killed during three days of clashes. The hostility has intensified as Congo voters prepare to select a leader in a run-off election in late October.

For weeks, Obama had been planning to visit Congo. He had hoped to promote his first stand-alone Senate bill that was designed to provide $52 million in assistance to Congo, a 25 percent increase from previous years.

But security conditions would not allow Obama to enter the country Thursday as planned.