Hamas has pushed back after being criticised by US Secretary of State Antony Blinken for not yet accepting a ceasefire proposal, saying it had shown "positivity" towards the negotiations.
The group said it had "dealt positively... with the latest proposal and all proposals to reach a ceasefire agreement".
It said, in contrast, "while Blinken continues to talk about 'Israel’s' approval of the latest proposal, we have not heard any Israeli official voicing approval".
Mr Blinken has repeatedly said that Israel has accepted a ceasefire proposal outlined by President Biden on 31 May. Israel's government has not officially said so, though an Israeli plan formed the basis for Mr Biden's declaration.
Speaking in Qatar on Wednesday, Mr Blinken expressed frustration with Hamas's response to the Israeli ceasefire proposal, which the group delivered on Tuesday.
The details of the response have not been made public, though Mr Blinken said Hamas had proposed changes, some of which, he said, were unworkable.
"At some point in a negotiation – and this has gone back and forth for a long time – you get to a point where if one side continues to change its demands, including making demands and insisting on changes for things that it already accepted, you have to question whether they’re proceeding in good faith or not."
But in a series of statements on Wednesday night, Hamas questioned whether Israel had actually accepted either the plan or a UN Security Council resolution endorsing it.
"The world did not hear any welcome or approval from [Israeli Prime Minister Benjamin] Netanyahu" and his government to the resolution, it said. "Rather they continued to emphasise the rejection of any permanent ceasefire, in clear contradiction with the Security Council resolution and President Biden’s initiative."
Hamas said that on the other hand, it had "clearly expressed its positive position on what was included in US President Joe Biden’s speech" and on "what was included" in the resolution. It also said it had confirmed its "readiness to co-operate" with the mediators involved in the ceasefire negotiations.
After a meeting with Mr Netanyahu in Jerusalem on Monday, Mr Blinken said the prime minister had "reaffirmed his commitment" to the ceasefire proposal.
Mr Netanyahu has not publicly endorsed the plan, although the war cabinet which he leads authorised the proposal which was delivered to Hamas on 27 May. That proposal - reportedly lengthier than the summary presented by Mr Biden - has not been made public and it is unclear whether it varies from what the president conveyed in his televised statement at the end of last month.
One of the main sticking points between the two sides appears to be their visions for ending the war. Reports say Hamas is insisting first on written guarantees that Israel will end the war before it will sign up to the plan. Mr Netanyahu has said the war will not end until Hamas's "governing and military capabilities" have been destroyed and the hostages returned.
The war began after Hamas attacked Israel on 7 October, killing about 1,200 people and taking 251 others back to Gaza as hostages. The Hamas-run health ministry says more than 37,000 people have been killed in Israel's offensive since then.
