South Sudan accused its northern rival Sudan Wednesday of conducting new airstrikes and shelling within its territory in direct violation of a U.N. Security Council resolution that aims to end hostilities between the two nations wrought from civil war.

A South Sudanese military official reported bombings by fighter jets and ground shelling in Bahr el Ghazal, Unity and Upper Nile states on Monday and Tuesday, which threaten to further weaken an already frail framework for peace negotiations as the two nations have been engaged in intensified border skirmishes in recent weeks.

Last week the U.N. called upon the two nations to agree to a peace process outlined by the African Union with both parties agreeing to a tenuous cease-fire.

Of course, automatically, this is a violation (of the ceasefire). If we have a compromise and we are at peace and then I go and knife you in the back, what does that mean? South Sudan's military spokesperson Kella Dual Kueth said, Reuters reported.

Sudan has not yet responded to the allegations from the South, though its foreign minister expressed the country's commitment to the U.N. and A.U.'s peace plan.

We ... will stick to the Security Council resolution ... Why be afraid of dealing with the Security Council resolution? Dealing with it positively gives a chance for our friends to defend us, Sudanese Foreign Minister Ali Ahmed Karti said before parliament Wednesday, Reuters reported.

The U.N. has threatened sanctions on both nations if they fail to negotiate peace.

Sudan had conducted airstrikes on the South last month after Southern forces seized an oilfield near the border. Border skirmishes have gone on since the two nations formerly separated in July 2011 amid ongoing disputes over oil resources.