UNITED NATIONS, April 5 (Xinhua) -- UN Secretary-General Antonio Guterres on Thursday congratulated President-elect Julius Maada Bio and the people of Sierra Leone for their successful and peaceful election process.

But, at the same time, the secretary-general appeals for continued calm and stresses the need for all stakeholders to seek redress of any grievances that could arise through established legal means, said a statement from the chief UN spokesman, Stephane Dujarric.

The secretary-general congratulated Maada Bio, the opposition candidate, on his election as the next president of Sierra Leone and all the candidates for their contributions to the successful outcome of the electoral process.

"He also applauds the people of Sierra Leone for the sense of responsibility that they have demonstrated in successfully completing the elections in a peaceful manner," the spokesman said.

There had been reports of violence and irregularities during the first round of balloting.

Dujarric released the statement following Wednesday's announcement in the capital of Freetown by the National Electoral Commission of the final results of the presidential run-off election.

Maada Bio narrowly defeated the ruling party candidate, Samura Kamara.

"The secretary-general commends the efforts of the national, regional and international electoral observation teams as well as those of his special representative for West Africa and the Sahel, Mohammed Ibn Chambas," the spokesman said.

"The secretary-general reiterated the support of the United Nations to the new government in consolidating peace and pursuing sustainable development," Dujarric said.