JUBA, South Sudan — South Sudan on Monday announced dramatic limits on a 4,000-strong new peacekeeping force a day after accepting its deployment, saying anyone who enters without consent is an “invader.”

The statement challenges the agreement reached by the visiting U.N. Security Council, which has threatened an arms embargo if turbulent South Sudan doesn’t comply. The council met President Salva Kiir on Sunday and emerged with a joint statement accepting the new U.N.-mandated force.

But on Monday, Cabinet Minister Martin Elia Lomuro told reporters the government must agree on the number of troops, the countries they come from and the arms they carry.

Minister of Information Michael Makuei said there will be no force if the conditions are not met.

“4,000 is the ceiling, but we are not duty-bound. We can even agree on 10,” Makuei said.

South Sudan, devastated by civil war, has said the force violates its sovereignty. The U.N. already has 12,000 peacekeepers in the country, and South Sudan has been wary of giving it more authority.

U.S. Ambassador Samantha Power on Sunday said details needed to be worked through but called that normal for a peacekeeping deployment.

The new force has a focus on protecting civilians. When fighting erupted in the capital, Juba, in July, hundreds were killed and residents feared a return to civil war in the already devastated country.

Both civilians and foreigners, including aid workers, were targeted in the chaos by South Sudanese soldiers who raped women and girls, conducted mock executions and forced people at one hotel compound to watch a local journalist be shot dead.

The visiting Security Council diplomats met with civilians who pleaded for the new protection force.

“I want this country to be peaceful so my children can go back to school,” said Rebecca Julio, a mother of four.