The Israeli army has said that it has determined that Hadar Goldin, the 23-year-old soldier it said was captured by Hamas on Friday, was killed in action.

The army had previously said that Goldin went missing when its soldiers, two of whom were killed, were attacked while trying to destroy a Hamas tunnel in southern Gaza.

In a statement, the army said Goldin "was killed in battle in the Gaza Strip on Friday".

An army spokesman refused to confirm or deny that the soldier's remains had been found, the AFP news agency reported.

There were reports that the military had come to the conclusion after examining DNA evidence.

Al Jazeera's James Bays, reporting from West Jerusalem, said there was "some speculation that he was not killed by Hamas but by Israeli bombardment in that area".

Israeli media had watched as Israeli Defence Minister Moshe Yaalon and the army Chief Rabbi Rafi Peretz visited the home of Goldin's parents earlier on Saturday.

Hundreds of people, including the parents of three young Israeli settlers killed in the occupied West Bank in June, also assembled at the Goldin family home in central Kfar Saba.

Earlier on Saturday, Benjamin Netanyahu, Israeli prime minister, pledged to find Goldin, saying "it does not matter how much time" is needed.

"Israel will continue to make every effort to bring its missing sons home," he said in remarks made just after the missing soldier's mother made an appeal demanding there be no troop withdrawal until her son is found.

Netanyahu also said Israel was prepared to continue fighting Hamas in the Gaza Strip even after the army completes its primary mission of destroying cross-border tunnels from the Palestinian territory.

He said Hamas will pay an "intolerable price" should there be more attacks.

Izzat al-Rishq, a senior Hamas spokesperson, called Netanyahu's speech "a declaration of failure and defeat".

"Netanyahu's speech underlines his frustration and defeat, and the recognition of the failure of this aggression against our people in the Gaza Strip," he said, adding that the speech was a "desperate attempt to raise the collapsed morale of his army".

Qatar emir's statement

A diplomatic solution also appears unlikely to end the crisis as Israel declared earlier on Saturday that it would not attend the talks set in Cairo.

Later in the day, the Office of the Emir of Qatar Sheikh Tamim bin Hamad Al Thani announced that he had received a phone call from Ban Ki-moon, the UN secretary-general, during which he expressed his astonishment regarding the statement issued by Ban on Friday holding Hamas and other factions responsible for the violation of the ceasefire in Gaza.

Sheikh Tamim said the UN should have verified what exactly had happened before issuing its statement.

He called on the UN secretary-general to take a clear position towards Israeli crimes [committed] against the Palestinian people, the office said.

Sheikh Tamim also urged all parties to open the border crossings in order to allow the humanitarian assistance into Gaza.

Meanwhile, bombardment continued across the Palestinian territory including the southern district of Rafah on Saturday afternoon, Al Jazeera's Imtiaz Tyab, reporting from Gaza, said.

The targets included a major mosque and a university.

Gaza's Health Ministry officials said the death toll since Israel began its offensive against Gaza on July 8 has now risen to 1,734 Palestinians.

Among those killed were 398 children, 209 women and 74 elderly men. There were also 64 soldiers and three civilians killed on the Israeli side.