Khartoum - Sudan could fall back into war if Washington fails to lift decades-old sanctions, Foreign Minister Ibrahim Ghandour has said, insisting that Khartoum sees the embargo as "unacceptable".US President Donald Trump is due to decide Wednesday whether to permanently lift the sanctions, which his predecessor Barack Obama eased in January.Obama made their removal dependent on Khartoum's progress in five areas of concern during a six-month review period ending Wednesday.Sudanese officials say Khartoum has fulfilled the Obama administration's conditions."We don't expect any other decision except lifting of the sanctions," Ghandour told state radio late Monday."Anything else will be illogical and unacceptable."He said the Trump administration's decision would have an impact on "war and peace" in Sudan, where fighting between the government and rebels has killed tens of thousands of people since 2003.Negotiations "If the sanctions continue, it will push the armed groups to harden their positions," Ghandour said."If the sanctions are lifted they will return to negotiations - if not, they will prepare for war."Obama's conditions included improved access for aid groups, counterterrorism co-operation with the US, an end to hostilities against armed groups in Sudan and halting support for insurgents in neighbouring South Sudan.Washington imposed a complex set of economic sanctions on Sudan in 1997 for its alleged backing of Islamist militant groups. Al-Qaeda leader Osama bin Laden, who was killed in a US commando raid in Pakistan in 2011, was based in Khartoum from 1992 to 1996.The US further justified the embargo with accusations that Khartoum was using scorched-earth tactics against ethnic minority rebels in war-torn Darfur - a region of the size of France.Unilateral ceasefire At least 300 000 people have been killed and 2.5 million displaced since fighting erupted in the western region in 2003, the United Nations says. The conflict broke out when ethnic African rebels took up arms against Khartoum's Arab-dominated government, accusing it of marginalising Darfur.Thousands more have been killed in similar conflicts in the southern states of Blue Nile and South Kordofan since 2011.Although Sudanese President Omar al-Bashir has declared a unilateral ceasefire in conflict zones, Khartoum and rebel groups have yet to sign a peace deal.United Nations aid agencies operating in Sudan have backed a full lifting of sanctions, saying they hope for a "positive" decision from Washington on Wednesday.