Nickolay Mladenov, the UN's special coordinator for the Middle East peace process, arrived in the Gaza Strip on Monday via the Beit Hanoun (Erez) border crossing.
Mladenov's visit has prompted speculation that a ceasefire between Israel and Hamas, the latter of which has governed Gaza since 2007, could be imminent.
On Sunday, a delegation of Egyptian intelligence officials departed Gaza following a two-day visit, during which they reportedly discussed truce proposals with Hamas officials.
One day earlier, Khalil al-Hayya, deputy leader of Hamas in Gaza, had said the Egyptian delegation would receive a "timetable" from Israel for the "implementation of the understandings".
What exactly these "understandings" are remains unclear. But the Israeli authorities on Monday morning increased the maritime zone in which Palestinian fishermen are permitted to ply their trade off Gaza's coast from nine to 15 nautical miles.
According to Israeli media reports, the move comes within the context of ongoing efforts to hammer out a truce between Israel and Gaza-based resistance groups, led by Hamas.
For months, Egypt, Qatar and the UN have led efforts to reach a ceasefire, which would reportedly involve Israel easing its blockade of Gaza while the Palestinians would be expected to scale back their ongoing rallies -- now in their second year -- along the Gaza-Israel buffer zone.
