JUBA, South Sudan – South Sudan is softening its rejection of a regional protection force a day after the U.N. Security Council voted to deploy the 4,000 additional peacekeepers to help restore calm. But a government spokesman said Saturday it will accept the force only if it can negotiate the size, mandate, weapons and contributing countries.

Presidential spokesman Ateny Wek Ateny said “the door is open” but would not say whether South Sudan has dropped its objection to the force answering to the existing U.N. peacekeeping mission.

The spokesman also said neighbouring Uganda, Sudan, Ethiopia and Kenya cannot take part.

An outbreak of deadly fighting in the capital, Juba, last month raised fears of a renewed civil war and saw attacks on civilians, aid workers and U.N. staffers.

South Sudan government officials have been vague about how they will respond if the new protection force enters uninvited. The government has expressed concern that giving the U.N. more control in the capital is the first step to losing the country’s sovereignty, and it has compared the deployment of a force without its approval to a return to colonialism.

In response, the U.S. deputy ambassador to the U.N. on Friday accused South Sudan’s government of blocking the work of the U.N. mission.

The Security Council on Friday also granted the more than 12,000 U.N. peacekeepers already in South Sudan expanded powers to use “all necessary means” to protect U.N. assets and to take “proactive” measures to protect civilians from threats.

The U.N. mission has been accused multiple times in South Sudan of failing to protect civilians, including in cases where government forces allegedly committed rapes outside U.N. camps.

South Sudan’s civil war began in December 2013, and a peace deal reached in August 2015 has been threatened by continued outbursts of fighting.