There have been almost daily reports of Palestinians being killed while waiting for food since Israel partially lifted an 11-week total blockade on aid deliveries in May, following a two-month ceasefire.
Israel, along with the US, helped to establish a controversial new aid system run by the Gaza Humanitarian Foundation (GHF), but food and medicine shortages have worsened.
The World Health Organization has said that a quarter of Gaza’s population is facing famine-like conditions, according to its assessments.
Israel has accused Hamas of instigating conflict near aid sites, and said its troops have only fired warning shots and do not intentionally shoot civilians.
On Monday, the UK joined 27 other countries in calling on Israel to “immediately lift restrictions” on the flow of aid, adding its aid delivery model was dangerous and deprived Gazans of “human dignity”.
Sir Keir has faced recent pressure from some Labour MPs to take a stronger line on Israel, including calls for the government to change its position and recognise a Palestinian state.
The government said it would only do so as part of a long-term political solution to the conflict in the Middle East.