JUBA, Jan. 26 (Xinhua) -- South Sudan on Friday summoned the U.S. Charge d'Affaires Michael Morrow over what it said are inflammatory and derogatory remarks by the U.S. ambassador to the UN Security Council.

The Ministry of Foreign Affairs Undersecretary Bak Akol Valentino, said the Wednesday remarks by ambassador Nikki Haley that the South Sudan Transitional Unity government (TGoNU) led by President Salva Kiir is unfit partner in bringing peace to end the four-year conflict.

"We just concluded the meeting with Charge d'Affaires, he tried to explain why Haley made that strongly worded statement at the Council, and we also asked him to convey to his government the strong feeling that the government of South Sudan has over that statement. We presented him with a protest note," Bak told journalists in Juba.

He disclosed that the inflammatory and defamatory statement on the situation in South Sudan was unjustified including the renewed call for imposition of arms embargo on South Sudan.

Bak added that Haley forgot that South Sudan is a sovereign state and its leadership deserves respect.

"The government of South Sudan would like to register its concern and protest in the strongest terms possible against the recent unjustified remarks made by ambassador Haley," Bak said, adding that the people and government of South Sudan wish to foster good relations with the Trump administration.

He said South Sudan has endeavored to promote diplomatic dialogue with the Trump administration and welcomes any advice on bilateral issues.

Meanwhile, Bak also confirmed the recent controversial resignation of the South Sudan ambassador to Russia Telar Ring Deng and further regretted that the latter chose to quit his post in Moscow through Facebook after being summoned to report to Juba within 72 hours.

"One of our ambassadors in the Russian Federation has resigned, I learnt about this yesterday (Thursday) our government wrote to him asking him to come to Juba for consultation. We told him to come back to Juba within 72 hours; it's unfortunate that our ambassador instead of coming back to Juba chose to resign," Bak said.

South Sudan descended into violence in December 2013 after political dispute between President Salva Kiir and his former deputy Riek Machar led to fighting between mostly Dinka ethnic soldiers loyal to Kiir against Machar's Nuer ethnic group.

The 2015 peace agreement to end the violence was again violated in July 2016 when the rival factions resumed fighting in the capital forcing Machar to flee into exile.

The conflict has killed tens of thousands of people and displaced millions that have sought refuge in neighboring countries.