The NGO bill, passed by the South Sudanese parliament on Tuesday, seeks to regulate the work of NGOs in the country, requiring them to register with a government commission, and imposing a 20-percent limit on the employment of foreign personnel.
"If the bill is implemented in a way that creates a more regressive environment, then this will have potentially catastrophic effects for the large amounts of the South Sudanese population that rely on NGOs to provide basic services and life saving aid," the Forum was quoted as saying by The Guardian.
The United Nations and its specialized agencies, along with the Red Cross and Red Crescent, are exempt from having to register.
South Sudan has been engulfed in a civil war since December 2013, when the country's president, Salva Kiir, accused his ex-deputy Riek Machar of plotting a coup. The hostilities in the country have intensified over the recent days amid clashes between the government forces and rebel groups.
On Monday, the International Committee of the Red Cross (ICRC) said that it had been forced to withdraw key staff from South Sudan amid a surge of violence in the country. The ICRC called on all parties to the conflict not to impede the work of humanitarian organizations and medical personnel in the area.
According to United Nations Office for the Coordination of Humanitarian Affairs (OCHA), more than 300,000 people in South Sudan are left without life-saving assistance. UN Mission in South Sudan (UNMISS) estimates that the number of people in need in 2015 will include 1.95 million internally displaced people and an expected 293,000 refugees.