Conricus described the tunnel as "very substantial", adding that it had communication systems, air vents, electricity and reinforced concrete structure. He said forces had detected the tunnel months ago and continued to monitor construction efforts by Hamas militants before demolishing it.
Israeli troops stationed on the borders between southeast Gaza Strip and Israel shot and wounded six Palestinians on Thursday, medical sources said.
"There seems to be a change, a paradigm here in how these terror tunnels will be able to threaten us in the future", he said.
It also came as Palestinian factions tried to meet Sunday's deadline for an Egyptian-mediated handover of Gaza by Hamas to Western-backed President Mahmoud Abbas after a decade's schism. It was located about 1 kilometer from an Israeli community.
The IDF added that it "holds Hamas exclusively responsible for all hostile acts against Israel emanating from Gaza Strip".
Conricus said a new system involving combat units, military intelligence, logistics and research had been used to destroy the tunnel. Meanwhile, Hamas's "restraint" forces are preventing rocket-launchers from reaching the Israeli border area, as attempted launches towards Israel have landed in Gaza.
Jerusalem remains at the heart of the Israel-Palestine conflict, with Palestinians hoping that East Jerusalem - now occupied by Israel - might eventually serve as the capital of a future Palestinian state.
Hamas' military wing issued a statement earlier Sunday threatening Israel with a "heavy price".