The relationship between South Sudan and the United Nations is souring during a critical time of conflict and mass death inside the world's newest country.

After a month of fighting between the government and rebels loyal to former Vice-President Riek Machar, the U.N. suddenly finds itself under verbal attack from South Sudan. The president has accused the top U.N. representative here of wanting to be co-president, and an Information Ministry spokesman said the U.N. has no respect for the government.

"We are not just at war against Riek Machar's rebels but also the U.N.," spokesman John Kelei said.

President Salva Kiir's spokesman on Wednesday continued the government's assault, saying the U.N. is sheltering armed rebels in its camp in Bor, the capital of Jonglei state. Ateny Wek Ateny said sheltering fighters is not part of the mandate of the U.N. mission, known as UNMISS.

"The president has not given the green light to attack UNMISS, but UNMISS has to rethink their strategies," Ateny said in response to a question. He also accused a U.N. employee of sending text messages that told rebels that pro-Machar residents inside a U.N. camp in the capital would join the rebels to topple the government.

The U.N. on Wednesday pushed back publicly.

"The U.N. recognizances the legitimate and democratically elected government of South Sudan, and (is) not taking sides during the conflict," Ariane Quentier, a spokeswoman for the U.N. mission here, said on a U.N. radio station.

Her announcement responded to Kiir's accusation Monday that the U.N. is running a "parallel government" and protecting rebels. The government became angered after a government minister was refused entry Sunday into the U.N. base in Bor.

"People go to them with guns," Kiir, speaking of refugees inside the camp, told a news conference. "I asked (the U.N.) to give us the guns and give us back our government vehicles that are parked outside by officials who have run away and joined the U.N. compound."

The attacks on the U.N. come as the government shows signs of being emboldened diplomatically. In Ethiopia, where peace talks are being held, Mabior De Garang, an official with the rebels, said the government is delaying talks because it is in a strong position after winning back two rebel-held state capitals in recent days.

"They feel they are now strong so they don't really need the peace process," said De Garang.

He said rebels had dropped their demand for the release of 11 top political prisoners before talks could proceed.

Thousands are believed dead and half a million people have been forced from their homes since fighting broke out Dec. 15 between troops loyal to Kiir and followers of Machar.

Kiir directly criticized U.N. Secretary-General Ban Ki-moon, who issued a statement expressing "alarm" that the government minister and his entourage tried to force their way into the U.N. compound.

Paul Jacob, an official who was on the Sunday trip with Information Minister Michael Makuel Lueth, said the U.N. gave no reason for preventing the government group from entering the camp with a camera crew. "It was very poor and embarrassing from a so-called partner," Jacob said.

One possible reason behind the war of words could be last week's visit by U.N. Assistant Secretary-General for Human Rights Ivan Simonovic. He announced evidence of mass atrocities by both sides. The government blames the rebels for any atrocities.

Violence escalated so quickly after Dec. 15, according to Simonovic, because no one was ever held accountable for massacres in 1991, when Machar led a revolt.

John Ashworth, an analyst with three decades' experience in the region, noted that international donors would not fund a badly needed reconciliation process.

"The international community is out of touch with South Sudan and have their own priorities. They do have a lot to answer for," he said.

Meseret contributed from Addis Ababa, Ethiopia.