* A week after last visit, Kerry to meet Netanyahu, Abbas
* Seeks framework peace agreement ahead of final deal
* Looks to allay Palestinian concern over security plan
U.S. Secretary of State John Kerry arrived back in the Middle East on Thursday, a week after his previous visit ended in Palestinian unhappiness over U.S. security ideas for an elusive land-for-peace deal with Israel.
Kerry, who has quipped that he is becoming a commuter to the region, headed off for talks with Palestinian President Mahmoud Abbas as soon as his plane landed and was due to see Israeli Prime Minister Benjamin Netanyahu on Friday.
Israel and the Palestinians resumed direct peace negotiations in July after a three-year break, hoping to end their decades-old conflict within nine months. However, there has been little public sign of progress, with both sides accusing the other of dragging their feet.
Kerry has said he presented Israel and the Palestinians last week with "some thoughts" on security arrangements in any future accord, but has given no details.
A Palestinian source said the security proposal outlined an Israeli military presence in the Jordan Valley, which is in the occupied West Bank, for 10 years. Abbas rejected the idea.
Looking to win him over, retired U.S. General John Allen, who has been working on possible solutions to allay Israeli security concerns, was due to join Kerry in the West Bank city of Ramallah for Thursday's meeting with the Palestinian leader.
"It is the first time that Gen. Allen is doing a briefing with President Abbas," a senior U.S. official said, declining to be named. Until now Allen, a former commander of U.S. troops in Afghanistan, has only briefed the Israelis on his ideas.
Israel has long said it wants to keep a military presence in the Jordan Valley between the West Bank and Jordan, in what would constitute the eastern border of a future Palestinian state, arguing that this is vital for national security.
Israeli and U.S. officials have signalled that Washington is trying to achieve a framework agreement on all major issues that would be fulfilled in phases. A senior State Department official said such an accord would guide the talks towards a final status deal which is slated for the end April.
"Our timeline has not changed, the commitment of both parties to nine months has not changed and our focus on a final status agreement has not changed," the official said.
The Palestinians fear that a framework accord could delay a full resolution to the conflict, and Abbas on Thursday ruled out any partial measures.
"We will not accept an interim deal. We will accept a final agreement that can be implemented in stages," he said in an interview with Sky News Arabia Television.
Israeli security worries are believed to be holding up the negotiations, with Netanyahu warning that Islamist militants could use the West Bank to launch rocket attacks at Israel unless Israeli troops remain deployed on all the borders.
"Our security must be in our own hands," Israeli Strategic Affairs Minister Yuval Steinitz told Israel Radio.
"I know it is hard for (the Palestinians) to swallow but they will have to accept ... that Israel has security interests it cannot forgo, and if they want peace, they must make significant compromises."
However, Abbas ruled out again on Thursday allowing any Israeli soldiers to stay along the fertile Jordan valley.
"If America wants to protect the security of Israel, they can go there (to the Jordan Valley), but we will not accept Israel being there," he said.
In Washington on Saturday, U.S. President Barack Obama said the Palestinians had to recognise there would be a transition period. "They (the Palestinians) don't get everything that they want on Day One. And that creates some political problems for President Abbas, as well," Obama said.