Both sides must "conclude the negotiations over the transfer of power to a civilian-led transitional authority as soon as possible," the U.N. official said in a statement.
Past discussions drew to a halt in the face of disagreements over whether the transitional body should be lead by a military or civilian figure.
On April 11, after ruling the country since 1989, Omar al-Bashir was ousted and arrested by the army. His downfall came after four months of nation-wide protests which witnessed the deaths at least 90 people according to the Central Committee of Sudan Doctors (CCSD), and the imprisonment of many other demonstrators.
After the Bashir stepped down, former Defense Minister Lieutenant-General Ahmed Awad Ibn Auf announced the establishment of a two-year transitional military council of which he was sworn in as a head. Protesters did not accept this as Ibn Auf is seen as a Bashir loyalist.
Since then thousands of protesters have been camping outside army headquarters in the capital city of Khartoum demanding a quick transition to a civil government.
In mid-May, at least nine people were wounded when Sudanese forces used live ammunition to clear demonstrators from central Khartoum, a protest group said. The CCSD also claims a pregnant woman was killed Wedndesday in crossfire between security groups.
On Friday, the offices of Al Jazeera Television in Sudan were ordered shut and the network’s license withdrawn by the country's Transitional Military Council (TMC).
According to the director of the Khartoum branch, officers appeared at the media outlet, seized their belongings and announced to them that the TMC had revoked the work permits of all staff members and correspondents effective immediately. The also banned the channel.
Al Jazeera released a statement denouncing the "abrupt" closure of the bureau and the censoring of its reporters, calling it "a complete violation of the freedom of the press."
No reason was given for the closure of the news agency's offices.
Guterres demanded that the “utmost restraint” be observed in order to preserve human rights and the right to the freedom of expression and assembly.