US Secretary of State Condoleezza Rice has urged Israel not to seal off the Gaza Strip following its planned withdrawal from the area next month.
Ms Rice was on her third visit to the Middle East in five months
Ms Rice met Palestinian leader Mahmoud Abbas one day after talks with Israeli Prime Minister Ariel Sharon.
Palestinians say Israel has not offered assurances over access, including the free movement of goods and people.
Israel has voiced concerns that the pullout will be met by an increase in violence by Palestinian militants.
Speaking in the West Bank town of Ramallah, Ms Rice said a well co-ordinated pullout could "re-energise" the peace process.
"We are committed to connectivity between Gaza and the West Bank and we are committed to openness and freedom of movement for the Palestinian people," Ms Rice added.
Ms Rice said more communication between Israeli and Palestinian officials was necessary to help ensure a peaceful and permanent withdrawal.
The BBC's Nick Thorpe, in Jerusalem, says Ms Rice firmly delivered Israel's message to her Palestinian hosts that security is the priority.
But Palestinians fear their own message that time is running out to resolve crucial problems in Gaza was not delivered to the Israeli government with the same force, our correspondent adds.
Earlier talks with the Israeli leader were described as "excellent"
Mr Abbas said on the eve of the meeting in the West Bank city of Ramallah that he needed to know more from the Israelis about the withdrawal.
"I will tell her: 'Dr Rice, we need answers from the Israelis,'" he said in an interview for Reuters news agency.
"Is Gaza going to be turned into a large prison? The Israelis are not co-operating."
He said Israel should provide information about logistics, and about the fate of border crossings and the Palestinian airport.
Speaking after meeting Mr Abbas, Ms Rice said the Palestinian Authority should do more to stem violence before the planned pullout.
Israel's disengagement plan involves the evacuation of more than 8,000 Israelis from 21 heavily-fortified settlements in the Gaza Strip, and hundreds more from four settlements in the northern West Bank.
Israel has occupied Gaza, the West Bank and East Jerusalem since 1967.
Ms Rice's hastily-arranged three-day visit to the Middle East began with talks with Mr Sharon on Friday.
She then made a surprise visit to Beirut, saying she wanted to show support for the new Lebanese government, the first elected for 30 years without Syrian influence in the country.