As it happened: Biden to visit Israel in show of support; Deal reached on humanitarian aid; Hamas releases video of 21-year-old hostage

It's currently Tuesday morning in the Middle East for Gazan residents who are attempting to flee before an expected Israeli ground invasion.

We're going to pause our live coverage of the conflict between Israel and Hamas for today.

Here's what made news throughout the day.

US President Joe Biden will travel to Israel, Secretary of State Antony Blinken said, as concerns increase the conflict Israel-Hamas war could expand into a larger regional conflict.

Israeli soldiers and reservists have been sent a letter by the head of the IDF, general staff chief Lieutenant General Herzi Halevi, in what seemed to be a pre-invasion motivational message to his troops.

A rapid response force of US Marines is headed to waters off Israel and is prepared for potential deployment, the Pentagon said.

And Deputy Prime Minister Richard Marles says the federal government has no more flights planned out of Israel, after he announced there are about twice as many Australians in Gaza than first thought.

We will be back with rolling coverage soon, otherwise you can stay up to date with the latest headlines at nine.com.au and 9news.com.au.

Palestinians in Gaza reported intense bombardments near the southern towns of Khan Younis and Rafah, where Israel ordered civilians to seek refuge, early Tuesday.

Details of causalities were not immediately available.

Israeli bombs hit areas west and south-east of Khan Younis and west of Rafah, according to local reports.

Thousands of people trying to escape Gaza are gathered in Rafah, which contains the territory's only border crossing to Egypt, as international mediators press for a deal to allow aid in and refugees with foreign passports out.

Saddening images of distressed Gaza residents are being captured as they attempt to evacuate their city.

More than 2000 civilians have already been killed in Gaza by Israel's airstrikes and more than 400,000 have been displaced.

A new day is currently beginning for the terrified residents.

See new images of the conflict here.

The Israeli military does not expect a planned visit by US President Joe Biden to complicate or delay any ground invasion of Gaza, a spokesperson told CNN on Tuesday.

Israel Defence Forces international spokesperson Lieutenant Colonel Jonathan Conricus said he believed Biden supported Israel's campaign to defeat Hamas.

"I think the president also said that 'Hamas needs to be destroyed,' and that is exactly our military aim," Conricus said.

Biden is scheduled to arrive in Israel on Wednesday local time.

Israeli airstrikes killed at least 28 people in Rafah early on Tuesday, according to a statement by the Palestinian Ministry of Interior.

Another statement from the ministry said airstrikes also killed and injured people in Khan Yunis, but did not provide an exact number.

A spokesperson for the Israel Defense Forces (IDF) would not confirm whether they launched strikes in those areas.

IDF international spokesperson Lieutenant Colonel Jonathan Conricus told CNN's John Vause he was "not aware of any strikes specifically in those areas but they could have happened".

"The combat operations continue. We continue to hunt Hamas operatives to attempt to degrade their military capabilities," Conricus said.

He said the hunt for Hamas targets was part of "the war that has been forced upon us" and Israel would continue military operations according to the law of armed conflict and of course to minimise civilian casualties.

A lack of clean water in the Gaza Strip is raising major concerns for human health.

"Gaza is running out of water, and Gaza is running out of life," said Philippe Lazzarini, chief of the UN agency for Palestinians.

Gaza normally gets its water supplies from a combination of sources, including a pipeline from Israel, desalination plants on the Mediterranean Sea and wells.

Those supplies were slashed when Israel cut off water, along with the fuel and electricity that power water and sewage plants in the wake of the Hamas attacks.

The United Nations recognises access to water as a human right, and on a basic level, the human body needs a constant supply of water to survive.

Israeli soldiers and reservists have been sent a letter by the head of the IDF, general staff chief Lieutenant General Herzi Halevi, in what seems to be a pre-invasion motivational message to his troops.

In the letter, which is dated to today, Halevi says the war against Hamas will be "difficult and long", but that Israel will prevail.

"We took a hard hit and we are responsible, but now the initiative is in our hands," he wrote.

"Every single one of you has a role in the challenges we face ahead. The war will be difficult and long and the IDF will prevail."

The letter contains several other indications that Israel's widely expected ground invasion of the Gaza Strip is drawing close.

"During this fateful hour, we are keeping our oath to protect our homeland and Israel's freedom and are fighting back," Halevi wrote.

"This is the eleventh consecutive day that the IDF is striking the enemy from the air, ground and sea. We destroyed enemy infrastructure, leadership and capabilities and caused significant damage.

"We will pursue and catch them everywhere and will strike them with force. We are determined and unified in our mission to protect our home and are prepared for any situation at every front.

"Our uncompromising responsibility is to overwhelm the enemy and restore security everywhere."

The letter finishes with the following message: "The citizens of Israel trust in you. I trust in you. Be strong and of courage".

The UN Security Council has rejected a Russian resolution that condemned violence and terrorism against civilians but made no mention of Hamas.

Only four countries joined Russia in voting for the resolution — China, the United Arab Emirates, Mozambique and Gabon.

Four countries voted against it — the United States, Britain, France and Japan. The other six countries abstained.

Adoption needs a minimum of nine "yes" votes in the 15-member council.

The UN's most powerful body, which is charged with maintaining international peace and security, has failed to respond to Hamas' attack on Israel which killed 1300 people and to Israel's response with retaliatory airstrikes that have killed 2750 and an order to Gazans in the north to head south to avoid an expected ground war.

Britain's UN ambassador, Barbara Woodward, said it would be "unconscionable for this council to ignore the largest terror attack in Israel's history".

With the Russian resolution rejected, she said negotiations would continue on a rival Brazilian resolution.

It also "firmly condemns all violence and hostilities against civilians and all acts of terrorism."

But it "unequivocally rejects and condemns the heinous terrorist attacks by Hamas".

It was unclear when the council will vote on the Brazilian resolution.