Several hundred activists, many from Europe, Canada, and the United States, plan to board 10 boats, including two cargo vessels carrying medicine and other aid, for a journey of several days across the Mediterranean to Gaza.
Israel's military has warned it will thwart any attempt to breach the sea blockade of the Palestinian territory, and it says it has trained for an operation that would minimize the potential for casualties.
Activists view Israel's blockade as a human-rights violation; Israel says the restrictions prevent weapons from reaching Iran-backed Hamas extremists who violently seized control of Gaza in 2007. Egypt also had a blockade on Gaza since 2007. After last year's confrontation, Israel significantly eased restrictions on cargo crossing into Gaza by land, and this month Egypt reopened its Rafah passenger crossing with Gaza.
The Israeli government Monday dropped a threat of lengthy deportation orders against journalists on the flotilla. On Sunday, Israel's Government Press Office had warned that any journalist caught on board the flotilla would be violating Israeli entry laws and could face deportation and a 10-year ban from the country.
In Athens, the loose coalition of activists' groups said it was ready to sail in the next few days but gave no specific date. They contended Greece was throwing up "administrative obstacles" in response to pressure from Israel.
Greece says it opposes the Gaza blockade but has urged Greek citizens and Greek-registered vessels not to participate in the flotilla, noting the risk of violence.