Israel carried out an air strike on militants in northern Gaza on Sunday, rattling an already fragile ceasefire as it prepared for fresh talks in Doha on the future of its truce with Hamas.

The Palestinian militant group has repeatedly called for an immediate start to negotiations on the ceasefire's second phase, which it hopes will lead to a permanent end to the war.

However, Israel says it prefers an extension of phase one until mid-April.

The disagreement over how to proceed came as the deal's first phase ended at the start this month, with Israel cutting off aid to the territory over the impasse.

Hamas representatives met mediators in Cairo over the weekend, emphasizing the urgent need to resume humanitarian aid deliveries to the besieged territory "without restrictions or conditions", a Hamas statement said.

"Hamas stresses the urgency of forcing the occupation to immediately begin second-phase negotiations under the agreed parameters," senior Hamas leader Mahmoud Mardawi told AFP, adding this would pave the way for a permanent end to the fighting.

Hamas's key demands for the second phase include a full Israeli withdrawal from Gaza, an end to the Israeli blockade, the reconstruction of the Palestinian territory and financial support, Mardawi said.

Following talks with mediators, Hamas spokesperson Abdel Latif Al-Qanoua said indicators were so far "positive".

A Hamas source said Sunday its delegation had now left Cairo for Doha.

Israeli Prime Minister Benjamin Netanyahu's office said it would send delegates to the Qatari capital on Monday, and Israeli media reported the security cabinet would discuss the matter later on Sunday.

Despite the end of the truce's initial phase, both sides have refrained from returning to all-out war, though there have been sporadic episodes of violence.

Israel's military said its air strike Sunday targeted militants who "were identified operating in proximity to IDF troops and attempting to plant an explosive device in the ground in northern Gaza".

The truce largely halted more than 15 months of fighting in Gaza, where virtually the entire population was displaced by Israel's relentless military campaign in response to Hamas's 7 October 2023, attack.

The six-week first phase revolved around the exchange of 25 living Israeli hostages and eight bodies for the release of about 1,800 Palestinian prisoners held in Israel.

It also allowed much-needed food, shelter and medical assistance to re-enter Gaza. 

After Israel again cut off the aid flow over the disagreement on the truce extension, UN rights experts accused the government of "weaponizing starvation".

"To date, only 10 percent of the required medical supplies have been allowed in, exacerbating the crisis," Gaza health ministry spokesman Khalil al-Dakran said, adding that the "continued closure of the crossings threatens the lives of patients in Gaza".

Displaced Palestinian widow Haneen al-Dura told AFP she and her children spent weeks living on the street "among dogs and rats" before receiving a tent.

"As the family's provider, it was distressing and I couldn't sleep at all during the night," she said.

'Last warning'

Last week, US President Donald Trump threatened further destruction of Gaza if all remaining hostages were not released, issuing what he called a "last warning" to Hamas leaders.

He also alluded to repercussions for all Gazans, telling them: "A beautiful Future awaits, but not if you hold Hostages. If you do, you are DEAD!"

Hamas said Trump's threats would only encourage Israel to ignore the terms of the truce.

The Trump administration has also confirmed the start of unprecedented direct talks with Hamas, which Washington had previously refused contact with since designating it a terrorist organization in 1997.

Of the 251 hostages taken by the Palestinian militants during the October 7 attack, 58 remain in Gaza, including five Americans. Four American captives have been confirmed dead, while one, Edan Alexander, is believed to be alive.

Trump had previously floated a widely condemned plan to expel Palestinians from Gaza, prompting Arab leaders to offer an alternative.

Their proposal would see Gaza's reconstruction financed through a trust fund, with the Ramallah-based Palestinian Authority returning to govern the territory.

"We need more discussion about it, but it's a good-faith first step," Steve Witkoff, Trump's Middle East envoy, told reporters in Washington in response to the Arab plan.

Witkoff will be returning to the region this week as he travels to Saudi Arabia for talks on the war in Ukraine.

At a weekend rally in Tel Aviv, family members of Israeli hostages demanded the government fully implement the ceasefire.

"The war could resume in a week," Einav Zangauker, the mother of Matan Zangauker, told the crowd. 

"The war won't bring the hostages back home, it will kill them."

Hamas's attack resulted in the deaths of 1,218 people on the Israeli side, most of them civilians, according to official figures.

Israel's retaliatory campaign has killed at least 48,458 people in Gaza, the majority of them civilians, according to the Hamas-run territory's health ministry. The UN considers these figures reliable.

by AFP team in Gaza City with Adel Zaanoun in Cairo