US Secretary of State Mike Pompeo has arrived in Sudan on a flight from Israel on the first visit of such a high-ranking US official for 15 years.
It comes as there is an increasing thaw in relations between the two countries.
Sudan wants to be removed from the US list of state sponsors of terror, while Mr Pompeo is promoting closer ties between Israel and Arab countries.
Relations between the US and Sudan have eased since last year’s overthrow of President Omar al-Bashir.
Earlier, Mr Pompeo had said he was on the first official direct flight from Tel Aviv to Khartoum, which was described as “historic” by the US embassy in Jerusalem..
The Sudan visit comes after he urged more Arab states to make a peace deal with Israel and follows the deal with the United Arab Emirates.
Sudan is on the US list of state sponsors of terrorism along with North Korea, Iran and Syria and wants to be removed so sanctions are lifted.
Sudan’s leaders are desperate to end the country’s economic isolation and gain access to the dollar-based international financial system to attract loans and investment.
They were put on the list on 1993 as al-Qaeda leader Osama Bin Laden lived in Sudan for five years in the 1990s as a guest of Mr Bashir’s government.
On his stop in Israel Mr Pompeo spoke about how he wanted stronger diplomatic ties between Arab nations and Israel – referring to the agreement UAE and Israel brokered by US President Donald Trump earlier this month.
We are “very hopeful we will see other Arab nations join in this”, he said.
It is only the third peace treaty between Israel and an Arab country.
Israeli Prime Minister Benjamin Netanyahu said the agreement heralded a new era, adding: “I hope we’ll have good news in the future, maybe in the near future.”
Israeli and US officials believe Bahrain, Oman and Sudan could be next.
However, Sudan’s foreign ministry sacked its spokesman last week after he praised the UAE’s peace treaty as “a brave and bold step”.