Latest figures from the Palestinian health ministry show attacks in Gaza have killed 630 Palestinians and wounded 4010.
More than 30 Israelis have been killed in the past 14 days of fighting.
An Israeli soldier was killed on Tuesday, the military said.
The US Federal Aviation Administration yesterday banned US flights into and from Ben Gurion international airport for up to 24 hours.
Other airlines, including Lufthansa, Air France and KLM, also announced flight cancellations.
As of last night, British Airways had not cancelled flights.
The UN has said more than 118,300 Gazans had been internally displaced, according to counts at 77 UN-run facilities.
And still the fighting continues.
At a joint news conference with Prime Minister Benjamin Netanyahu, Mr Ban urged Israel to exercise maximum restraint, adding that military action would not increase Israeli security in the long term.
He also called on Palestinians to pursue a policy of no violence, recognition of Israel and respect for previous agreements.
Mr Netanyahu has shown no will to stop the shelling of Gaza, solid in his belief that enemies surround Israel, wanting the country to be destroyed. But Israel's response must be proportional.
Hamas is using civilians to shield its rockets and sadly, the highest proportion of casualties have been innocent men, women and children.
As the days go by, there is a sad and familiar choreography to Gaza's recurrent wars.
As the news gets grimmer, the demands mount for urgent ceasefire.
The longer conflict continues, the more unlikely a peaceful solution will be found.
Many Israelis are uncomfortable with Gaza's high civilian death toll.
But a clear majority continues to support a military operation designed to limit Hamas' ability to fire rockets into Israel and to infiltrate territory.
A military spokesman said Israel had eliminated about half of the tunnels Hamas had dug out of Gaza and destroyed 30% to 40% of militants' rocket arsenals.
The extent of the cross-border tunnel network dug by Hamas has been a shock for some and Israelis want the threat removed.
Mediation is needed urgently but mediation is more complicated than ever.
In 2012, neighbouring Egypt, then led by the Muslim Brotherhood, had the most clout with Hamas.
This time, would-be peacemakers travel across the region from Qatar to Istanbul to Cairo looking for the right voice at the right time.
Hamas has rejected an Egyptian ceasefire proposal because, it said, it had not been consulted about the proposal and because it was a return to the status quo. Hamas' own ceasefire proposal is too far-reaching for Israel to accept.
The time has come for a peace-maker of influence to find a solution which allows Hamas to back away from the impossible task of subduing Israel and for Mr Netanyahu to order the attacks on innocents to stop.
Who is that peacemaker?
The world - and especially the people of Gaza and Israel - await.
And another thing LABOUR Party leader David Cunliffe needs to stop apologising.
His latest ''sorry'' - for spending private time with his family - was unwarranted.
Mr Cunliffe has been haunted by bad decision-making during recent weeks, most recently apologising for taking time out during the school holidays with his wife and two sons.
There is a colloquial phrase in New Zealand about having to ''man up'', and it is time the Labour leader took that advice.
Men should take time out with their families, when they can.
It is wrong and unnecessary for any man devoted to his family - like Mr Cunliffe - to apologise for taking a few days off before what will undoubtedly be a busy and stressful time ahead of the September 20 election.
The rot started when the sound bite emerged of Mr Cunliffe saying he was sorry for being a man because it was men who inflicted the worst of domestic violence.
Poor sentence phrasing seems have condemned Mr Cunliffe to an endless round of apologies.
He should stop saying sorry unless it is really necessary.
