"The discussions between Abbas and Mitchell on Wednesday will concern final-status issues with Israel," head Palestinian negotiator Saeb Erakat told AFP, referring to core disputes in the decades-old conflict such as Jerusalem and Palestinian refugees.
"For now we will focus on the issues of borders and security in order to demarcate two states along the 1967 border," he added.
He warned however that continued Israeli settlement activity, including in annexed east Jerusalem, could scupper the talks.
"The Israeli side has just two options, either peace or the continuation of the settlements. Israel cannot have both at the same time," he said.
US officials have said Mitchell is expected in the region this week but they have not yet said when he would arrive or released details about his schedule.
Mitchell left the region a week ago after convincing Israel and the Palestinians to launch an initial round of US-mediated "proximity talks."
The indirect negotiations were first agreed on in March but the initiative collapsed within days when Israel announced plans to build 1,600 settler homes in east Jerusalem during a visit by US Vice President Joe Biden.
The Palestinians eventually agreed to the talks after receiving US assurances that the project would be frozen.
Israel, which captured east Jerusalem in the 1967 Six-Day war and later annexed it, considers the Holy City its "eternal and indivisible" capital, a claim not recognised by the international community.
The Palestinians have always demanded mostly Arab east Jerusalem as the capital of their promised state.
The last round of direct negotiations between the two sides collapsed in December 2008 when Israel launched a devastating war on the Gaza Strip in a bid to halt Palestinian rocket fire aimed at Israeli towns.
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