He said he would arrive in Sharm el-Sheikh late Friday and meet Palestinian president Mahmud Abbas, Egyptian President Hosni Mubarak and Foreign Minister Ahmed Abul Gheit on Saturday before continuing on to Israel for high-level discussions late Saturday and on Sunday.
"Although humanitarian efforts must continue, the situation in the Gaza Strip and the entire Middle East can only change if we achieve a lasting and comprehensive ceasefire," Steinmeier told reporters.
His mission would be "closely coordinated" with the Czech presidency of the European Union, he said.
Cairo has put forward a plan calling for an immediate ceasefire for a specified period, opening Gaza's border crossings, preventing arms smuggling into the territory and an invitation to Palestinian factions to reconciliation talks.
But Palestinian groups including Hamas rejected the plan Thursday as having "no valid basis.”
German Chancellor Angela Merkel and French President Nicolas Sarkozy said after talks Thursday that Berlin and Paris would work together to obtain security guarantees for Israel in the hope of ending the fighting, including a stop to weapons smuggling into Gaza.
France has proposed reviving an EU monitoring mission to help Egypt prevent arms smugglers sneaking rockets and explosives to Palestinian militants in the Gaza Strip.
Meanwhile the UN Security Council voted Thursday to call for an "immediate, durable" ceasefire in the Gaza Strip leading to a "full withdrawal" of Israeli troops in a bid to bolster peace efforts in the region.
German deputy foreign minister Gernot Erler told public television Friday he would not rule out Berlin sending troops as part of a possible UN monitoring mission in Gaza if both the Israeli and Palestinian sides requested its participation.
Officials in Berlin had mooted the idea in recent days but the prospect of German troops potentially firing on Israelis would be deeply controversial due to Germany's Nazi past.
Israel launched its war against Hamas on December 27 aiming to end rocket attacks against southern Israel and the smuggling of weapons into Gaza from Egypt. Palestinian medics say almost 800 people have been killed since then.
Ten Israeli soldiers and three civilians have been killed in combat or rocket attacks into Israel over the same time. Hamas has demanded the end of Israel's blockade of Gaza since the Islamists seized power there in June 2007.