Sudan's parliament has declared South Sudan an “enemy” amid escalated violence along the countries' shared border.

After the vote Monday in Khartoum, South Sudanese Information Minister Barnaba Marial Benjamin rejected the decision, saying his country is not an enemy of Sudan.

Rabie Abdelati Obeid, a prominent member of Sudan's ruling National Congress Party, told VOA the situation between the two countries is “now a state of war.”

“They have started war, they invaded our area, and they distracted our localities and there is no way for any diplomacy.”

He said South Sudan is not respecting a 2005 peace deal that ended Sudan's north-south civil war.

“They don't understand [it]. And their mind is actually oriented to war and they don't know how to establish a country peacefully and how to establish relations and their culture is completely different than the culture of peace.”

South Sudan said Sudanese warplanes bombed parts of Unity State on Sunday, killing at least five people and wounding nine others.

The south also accused Sudan of bombing an oil field in the disputed border town of Heglig, which Juba's military seized from the north last week. Obeid denied accusations that the north used the area as a base to launch attacks against unarmed civilians in the south.

The current president of the United Nations Security Council said Monday the world body is gravely concerned about increasing confrontations along the two Sudans' border and deep into each other's territory.

The U.S. ambassador to the United Nations, Susan Rice, told reporters in New York that the Security Council will meet to discuss the crisis, perhaps as early as Tuesday.

Rice condemned recent airstrikes by Sudan's armed forces in South Sudan, particularly one that struck a U.N. peacekeepers' facility on Monday.

“This is obviously a subject of grave concern, as is the south's continued presence in Heglig and a myriad of violent confrontations in and around the border area and deep into both countries' territory.”

The U.S. envoy expressed concern about South Sudan's continued presence in Heglig, which is claimed by both the north and south.

A U.S. State Department spokesman said the U.S. envoy to Sudan, Princeton Lyman, met Monday with South Sudan's president, Salva Kiir, in Juba for talks on how to calm the situation.

“The tensions are far too high, the fighting has to cease and humanitarian access has to be granted.”

Oil fields in Heglig produce about half of Sudan's total oil output, and South Sudan's presence has sparked threats of retaliation from Khartoum.

In a recent letter to the Security Council, South Sudan's acting deputy representative said her country discovered last month that Sudan was building a new tie-in pipeline from Heglig oil fields in an attempt to siphon oil from Unity State in South Sudan.