The developments are being seen as important steps in a US-backed peace plan for the Middle East, known as the roadmap.
However, Israel is not happy with the truce announcement by the militant groups.
It wants the groups to be broken up completely - as required by the roadmap.
The US is pleased with the truce.
"Anything that reduces violence is a step in the right direction," said a US spokesman.
Condoleezza Rice, the US National Security Adviser, spent the weekend in the Middle East, urging leaders on both sides to press ahead with the roadmap.