"Israel's plan to annex Palestinian territories cause us great concern in what regards the security of Israel and the entire region", Maas said after a meeting with his French counterpart, Jean-Yves Le Drian.
Maas added that he would soon speak to the French minister about this again.
"The goal is, like before, to prevent this escalating to an annexation that would violate the international law", Maas said.
The statement comes after EU High Representative for Foreign Affairs and Security Policy Josep Borrell said that Israel's annexation of part of the Palestinian territories in the West Bank would violate international law.
In late May, Palestinian Authority President Mahmoud Abbas terminated all of its treaties with the US and Israel in response to the annexation announcement.
According to US President Donald Trump's so-called deal of the century unveiled in late January, Israel is to annex land in the West Bank and the Jordan Valley. Trump's deal proposes a two-state solution in the region that would allow for the creation of a demilitarized Palestinian state. Israeli Prime Minister Benjamin Netanyahu's unity government has supported the plan, while most Arab countries have totally rejected the proposal.
