Eritrea has rejected a U.N. Security Council resolution that threatens sanctions against Ethiopia and Eritrea if they use force to settle their border dispute.

Eritrea's government said Thursday the resolution could lead to more conflict in the region.

It also urged the Security Council to take more forceful action against Ethiopia, claiming Addis Ababa has failed to live up to international agreements to settle the border dispute.

The 15-member council passed the resolution Wednesday, demanding that the two east African nations reverse a troop buildup along their border.

Meanwhile, a spokeswoman for the U.N. mission in Ethiopia and Eritrea says about 20 Ethiopian troops entered a demilitarized buffer zone along the border.

She says the troops left after U.N. peacekeepers intervened.

Such tensions have heightened fears that the countries will repeat their 1998 to 2000 border war, which killed 70,000 people.