The South Sudan pound, launched last Monday in Juba, threatens to further devalue the Sudanese pound and has raised concerns about either country being flooded with old notes.
There are about 11 billion old Sudanese pounds in the north, and the south's central bank governor, Elijah Malok, urged the new country's 10 states to ensure the swiftest possible circulation of their new currency, saying otherwise "a lot of money will pour in and destroy our economy."
But Zubair sought to calm fears about any such move.
"We are ready to negotiate with the government of South Sudan about the old money that they have," he said.
Zubair hailed the launch of the new Sudanese pound as "the beginning of the second republic," echoing the words of Sudan's President Omar al-Bashir, on July 12, in his first speech to parliament after the south's declaration of independence.
Bashir called for understanding and patience at the start of the new era, as he outlined a package of austerity measures designed to bolster an ailing economy and accommodate the sharp fall in oil revenues.
The issue of currencies was one of a number of key outstanding topics that the north and south failed to agree on prior to the country's partition.