That's exactly what the negotiations are supposed to be about, that's exactly what the international community is interested in seeing happen, that's exactly what the UN and the Security Council have been calling for since 1967(Israeli withdrawal), and that's exactly what Israel should be preparing to do. Abbas' so-called "condition" - that all settlement building stop - is about ACKNOWLEDGEMENT! Because as long as Israel continues building and expanding settlements, regardless of any temporary limitations it may impose on them - it's not only refusing to acknowledge the purpose of the negotiatios, but it's also belying an inherent INTENT of them NOT bearing fruition. Otherwise, it would be a given, and prudent, for Israel to stop all settlement activity until an agreement is reached.
UN: Gaza could be 'uninhabitable' by 2020 if trends continue (AP)
from the article: Abbas sets conditions for direct talks with Israel