Israeli forces killed at least 55 Palestinians in airstrikes in Gaza on Tuesday, local medics said, continuing to bombard the enclave despite mounting international pressure to halt military operations and allow unimpeded deliveries of aid.

Britain announced it was suspending trade talks with Israel and summoning its ambassador over "egregious policies" in the occupied West Bank and Gaza, while European Union foreign policy chief Kaja Kallas asked for a review of the EU-Israel trade deal, according to Dutch news agency ANP.

The United Nations said no humanitarian aid had been distributed yet in Gaza, although Israel eased its 11-week-old blockade on Monday.

"Israeli authorities are requiring us to offload supplies on the Palestinian side of Kerem Shalom crossing and reload them separately once they secure our team's access from inside Gaza," said U.N. spokesperson Stephane Dujarric.

Israel's military said 93 UN aid trucks entered Gaza on Tuesday via Kerem Shalom "after a thorough security inspection".