US President Barack Obama is due to meet Israeli Prime Minister Benjamin Netanyahu in Washington.
They are expected to discuss a range of issues, including Iran's nuclear programme and efforts to start direct Israeli-Palestinian peace talks.
The meeting comes a day after Israel confirmed it would allow more consumer goods to enter the Gaza Strip.
But it said items including weapons and materials that could have a military use would be barred or limited.
The White House, EU and Britain have welcomed the move as a "significant step" forward.
But Hamas, which has been controlling Gaza since 2007, dismissed the concessions as of no use and said the blockade should be fully lifted.
Israel says its blockade of the Palestinian territory is needed to prevent the supply of weapons to Hamas.
'Better atmosphere' Last week Mr Netanyahu said he believed that a main part of his talks in Washington would be "focused on how to start direct peace talks between Israel and the Palestinians right away".
Analysis
Continue reading the main storyMr Netanyahu says he has listened and has since bent over backwards to accommodate Palestinian demands - making positive gestures like the freezing of new settlement building in the occupied West Bank.
Palestinian leaders say the Israeli moves are hollow. Officials emphasise the fact that existing, not new, construction continues apace.
Analysts say we should not expect too much. Mr Netanyahu does not have much more room for manoeuvre. Members of his right-wing coalition are already demanding a complete resumption of all building in the settlements in September - on the occupied West Bank and in East Jerusalem.
Analysis: Little room to manoeuvre Send us your comments
The start of indirect negotiations in March was halted after Israeli municipal authorities approved plans for the construction of new homes in a settlement in East Jerusalem, which Palestinians want as the capital of a future state.
When the Israeli premier last visited the White House in March, he was snubbed by President Obama, who refused even to allow a photo of their meeting to be released.
That was because of a row over an Israeli settlement plan in East Jerusalem.
Both sides want the atmosphere this time to be much better, the BBC's Middle East editor Jeremy Bowen says.
He says Mr Obama and Mr Netanyahu will have plenty to talk about: what comes next in the gathering storm over Iran's nuclear programme; the changing strategic picture in the Middle East, epitomised by Turkey's public falling out with the Israelis; and how to establish a credible peace process with the Palestinians.
However, he adds that - unlike his predecessor - President Obama is prepared to accept that some of Israel's actions are part of the problem in the Middle East. This continues to create irritation - and nervousness - on the Israeli side.
During his three-day US visit, Mr Netanyahu is expected to travel to New York, where he will meet UN Secretary-General Ban Ki-moon and address Jewish American leaders.
US First Lady Michelle Obama has also taken the unusual step of inviting Mr Netanyahu's wife, Sara, for a visit to the White House, the Israeli media reported.
Gaza visit Israel came under international pressure to ease its four-year blockade of Gaza after nine Turkish activists were killed in a 31 May Israeli raid on a flotilla that was trying to carry aid to the Palestinian territory.
GAZA BLOCKADE EASED
Continue reading the main story- Consumer goods allowed
- Weapons and ammunition banned
- Goods with dual civilian/military use banned
- Construction materials restricted
- Sea blockade of Gaza remains
- Exports banned
"This step shows that it is possible to lift the pressure on ordinary Gazans without compromising the security of ordinary Israelis," Britain's Foreign Secretary William Hague said.
He urged all parties to work together to deliver "real change on the ground".
Meanwhile, a group of European foreign ministers said they would visit Gaza at Israel's invitation to monitor the implementation of Israel's plan to ease the blockade.
Spanish Prime Minister Jose Luis Rodriguez Zapatero said the ministers from Britain, France, Italy and Spain would go this month.
BBC
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