|John Kerry, right, is one of a number of envoys in Sudan for the referendum [Fatma Naib/Al Jazeera]
John Kerry, the US senator for Massachusetts, has called comments by Sudan's president on the country's upcoming referendum on southern succession "extremely encouraging" during a visit to Khartoum, the Sudanese capital.
Omar al-Bashir pledged last week to help build a stable and "brotherly" southern state if it votes for independence on January 9.
The president echoed those comments on Tuesday when he visited the southern capital of Juba, saying he would celebrate the results of the referendum even if the south chooses to secede.
Kerry, who is chairman of the Senate foreign relations committee, is one of a number of international envoys who are in the country ahead of the referendum which could see Sudan's south establish itself as an independent nation.
"The speech by President Bashir here [in Khartoum, on December 31], as well as his comments in Juba yesterday are extremely encouraging," Kerry told reporters following a meeting with Ghazi Salaheddine, an influential presidential adviser, on Wednesday.
"They're very positive, very constructive, and I think it sets a good stage for the events that begin in the next days."
Kerry also said that it was "in the interest of the US to have a stronger and better relationships with the Sudan".
The senator indicated that Washington could remove Sudan from its list of state sponsors of "terrorism" early if the referendum is judged to have gone smoothly.
But he stressed that this would not affect US sanctions against Khartoum related to Darfur.
Sudan faces huge economic problems, including soaring inflation, caused by the sharp devaluation of the Sudanese pound over the past three months, and large external debts.
"Obviously there are huge economic challenges [in Sudan] and that's something that we discussed today," Kerry said without elaborating.
Salaheddine, asked whether the US was offering Sudan any new incentives to help the country confront its economic challenges, said nothing concrete had been proposed.
"We haven't seen much so far," the presidential adviser said.
"They bring it up every time we discuss the issue of Darfur and the future relationship with the United States," Salaheddine said.
"This [question of economic support] is more of a bilateral issue actually than one relating to the south or Darfur, even though in the United States they like to see them as interconnected."
Darfur has been gripped by a civil war since 2003 that has claimed 300,000 lives and displaced 2.7 million people, according to UN figures. Khartoum says 10,000 people have died in the conflict.
Kerry, a former US presidential candidate, has made three prior trips to Sudan.