Sudan on Sunday threatened to put on hold nine security and economic pacts with South Sudan, including one on vital oil shipments, if its neighbour continues its alleged support for rebel groups.

Sudan's President Umar al-Bashir over the weekend accused his neighbour of arming the rebel Sudan People's Liberation Movement-North group in his territory and ordered the closure of pipelines carrying oil from the landlocked South through his country to Port Sudan on the Red Sea - currently the South's only export route.

Bashir's order comes after he threatened on May 27 to close oil pipelines from South Sudan "forever" if South Sudan gives support to rebels in the western Sudanese region of Darfur and the Blue Nile and Southern Kordofan states.

"Sudan won't allow revenue from oil exports from South Sudan to be used for buying arms for rebels and mercenaries," he said on Saturday.

Sudan's Information Minister Ahmed Belal Osman said Khartoum will act out its threat within 60 days "but if South Sudan is serious ... and stops backing rebels, if we get international guarantees for that, then our door is open and we can reverse the stoppage."

The announcement threatens to bring the two nations back to the brink of confrontation after months of relative peace.

Despite the South's independence in 2011 after a two-decade civil war, tensions over oil and land have flared up regularly. South Sudan took with it nearly three-quarters of Sudan's oil production when it declared independence and the two sides fell out over how much the South should pay to export its oil through Sudanese pipelines.

South Sudan officials said it may stop oil production if Khartoum carries out its threat and accused Sudan of "blackmail" by regularly threatening to block Juba's oil shipments.

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South Sudan's Minister of Information Barnaba Marial Benjamin said, while Juba has yet to receive an official communication about Bashir's intentions, Khartoum cannot unilaterally revoke the "Cooperation Agreement" without first consulting with South Sudan.

Oil started flowing again in April after both sides struck a deal and a confirmed oil stoppage would dash hopes of an economic lifeline to both underdeveloped countries.

Related: Sudans Agree To Resume Oil Exports Within Three Weeks

The last shutdown in July 2011 ravaged both their economies as oil was the main source of state revenues and the monies needed to pay for food imports.

Economy Watch