"It's not enough to have scattered measures -- we need a paradigm shift," Guterres told reporters at the UN's New York headquarters.
He had earlier said that in the aftermath of Israel's killing of seven humanitarian workers from World Central Kitchen, the UN "was informed by the Israeli government of its intention to allow a meaningful increase in humanitarian aid distributed in Gaza."
Israel announced on Friday that it would allow "temporary" aid deliveries into famine-threatened northern Gaza, hours after the United States warned of a potential shift in its policy over Israel's war against “Hamas”.
Palestinians in northern Gaza have eaten an average of just 245 calories per day -- less than a can of beans -- since January, according to the charity Oxfam.
Charities have accused Israel of blocking aid, but Israel had defended its efforts and blamed shortages on groups' inability to distribute aid once it gets in.
The bloodiest-ever Gaza war began with “Hamas”'s October 7 attack on Israel that resulted in the deaths of 1,170 Israelis and foreigners, most of them civilians, according to an AFP tally based on official Israeli figures.
Palestinian militants also took around 250 hostages, about 130 of whom remain in Gaza, including 34 whom the army says are dead.
Israel's retaliatory campaign has killed at least 33,091 people, according to the health ministry in “Hamas”-run Gaza, while the United Nations has warned of "catastrop