UN chief Kofi Annan has used talks in Jerusalem to demand an end to Israel's air and sea blockade of Lebanon.
Israel has maintained its air and sea blockade for weeks
Mr Annan, who flew to Israel from a visit to Lebanon, told Defence Minister Amir Peretz the "humiliating" blockade should be lifted as soon as possible.
Israel has previously made clear its concerns about the possible rearming of Hezbollah must be addressed first.
Mr Annan also said Israel had committed most of the violations reported in the two-week-old truce with Hezbollah.
Earlier, Mr Annan held a meeting with the families of the two soldiers whose capture sparked the crisis, Ehud Goldwasser and Eldad Regev.
Kofi Annan met families of the captured Israeli soldiers
Mr Annan has urged Hezbollah to free the two captives speedily, and told the relatives that he would continue to press for their freedom.
Mr Annan had promised to do "everything in his power" to bring about their release, said Benny Regev, Eldad Regev's brother.
Mr Regev also said the UN chief had promised to push for "signs of life" of the captives.
Relatives of a third soldier, Gilad Shalit, who was captured by Palestinian militants in an earlier incident near the Gaza Strip, also attended the meeting.
Mr Annan's regional tour is aimed at bolstering the fragile ceasefire which ended more than a month of conflict between Israel and Hezbollah.
He flew to Tel Aviv by helicopter after witnessing the scenes of devastation in south Lebanon wrought during the conflict.
Before leaving Lebanon, Mr Annan described Israel's continuing embargo as "a humiliation and an infringement on [Lebanese] sovereignty".
The issue was among the key points raised at his meeting with Mr Peretz, his first with a senior politician after arriving in Israel.
Afterwards, Mr Peretz said he had emphasised to Mr Annan the issue of the transfer of weapons from Syria to Hezbollah, and Israel's concerns about Iran posing a threat.
He also said Israeli troops would remain in Lebanon for "several weeks, no longer than that", and would pull out once the UN's expanded peace force was on the ground in "reasonable" numbers.
Mr Annan said the force would number 5,000 "relatively quickly", to clear the way for the Israeli pullout.
Mr Annan will have talks on Wednesday with embattled Prime Minister Ehud Olmert, who - along with Mr Peretz - has been heavily criticised over the way the military action was conducted.
The BBC's Matthew Price in Jerusalem says that it is highly unusual to see the UN chief in Israel - with several Security Council resolutions outstanding against it - and many Israelis view the organisation with suspicion.
But put simply, Israel currently needs the UN, he says.
UN TROOP PLEDGES
France - leadership and 2,000 troops
Italy - 2,500-3,000 troops
Bangladesh - two battalions (up to 2,000 troops)
Malaysia - one battalion
Spain - one mechanised battalion
Indonesia - one battalion, an engineering company
Nepal - one battalion
Denmark - at least two ships
Poland - 500 troops
Finland - 250 troops
Belgium - 302 troops, later rising to 392
Germany - maritime and border patrols but no combat troops
Norway - 100 soldiers
Mr Olmert's only hope of regaining public support is a secure northern border - and that can only happen through the UN force, our correspondent says.
Before leaving Lebanon for Israel, Mr Annan met Lebanese leaders to discuss the force, which is to be expanded from 2,000 to a total of 15,000.
He later flew by helicopter from Beirut to the UN peacekeepers' headquarters in the southern port of Naqoura, in an area still occupied by Israeli troops and tanks.
There he reviewed an honour guard of UN troops on the lawn of the white-walled UN compound.
After about two-and-a-half hours, Mr Annan set off on an airborne tour of some of the areas in southern Lebanon most heavily bombarded by Israel during the 34-day conflict.
After visiting Israel, Mr Annan will travel on to Iran and Syria, countries with close links to Hezbollah.