Wadephul acknowledged that Israel had to be able to defend itself against attacks by the Houthis, Hezbollah or Iran.
"A different issue is whether what is happening in the Gaza Strip is consonant with humanitarian international law," he told the Süddeutsche Zeitung newspaper on Friday.
"We are checking this, and based on this evaluation, we will approve further arms deliveries where necessary."
He indicated that this could lead to a partial halt to deliveries.
Speaking to US broadcaster Fox News on Wednesday, Wadephul said that Germany stood with Israel and had responsibility for the security and existence of Israel in light of German history.
"We have delivered weapons, and we will do so in the future," he said.
Current aid deliveries to Gaza were a drop in the ocean, Wadephul said.
"This is about ensuring basic human rights. The sick and the weak and the children die first," Wadephul said.
"As a result, we have changed our language and will also probably change our political action in the next step."
There has been a shift in relations with Israel, indicated recently by Wadephul and Chancellor Friedrich Merz.
They believe Israel has not met its commitment to provide for the Palestinian population via the new Israeli-US distribution plan.