Israel's defence minister has approved a plan for the conquest of Gaza City and authorised the call-up of around 60,000 reservists to carry it out, his ministry confirmed on Wednesday.

Defence Minister Israel Katz's move, confirmed by a spokesperson, piled pressure on Hamas as mediators pushing for a ceasefire in the nearly two-year war in Gaza awaited an official Israeli response on their latest proposal.

While mediator Qatar had expressed guarded optimism over the latest proposal, a senior Israeli official said the government stood firm on its call for the release of all hostages in any agreement.

The framework that Hamas had approved proposes an initial 60-day truce, a staggered hostage release, the freeing of some Palestinian prisoners and provisions allowing for the entry of aid into Gaza.

Israel and Hamas have held on-and-off indirect negotiations throughout the war, resulting in two short truces during which Israeli hostages were released in exchange for Palestinian prisoners.