* Palestinians reject Netanyahu vow to annex Jordan Valley
* Move would splinter territory Palestinians want for state
* Netanyahu acts to outflank far-right rivals in election
* Palestinians see fertile valley as their "breadbasket"
* Israelis see it as security bulwark along Jordan border
* Netanyahu emboldened by warm relationship with Trump
By Adel Abu Nimeh
JIFTLIK, West Bank, Sept 11 (Reuters) - Palestinians tilling the fertile Jordan Valley said on Wednesday they have been rooted for generations to the West Bank land that Israeli Prime Minister Benjamin Netanyahu plans to annex, and they vowed never to give it up.
"We tell Netanyahu, and whoever follows him, you will not break the Palestinians' will, you will never break our will, never, never," said Hassan Al-Abedi, a farmer who lives in the village of Jiftlik.
"It's our parents' and grandparents' land. We will hold onto it no matter what it costs," the 55-year-old Abedi said.
Drawing condemnation from Palestinian and other Arab leaders , the right-wing Netanyahu announced on Tuesday that he intended to "apply Israeli sovereignty" to the Jordan Valley and adjacent northern Dead Sea if he prevailed in what is shaping up as a tough battle for re-election on Sept. 17.
Palestinians seek to establish a state in all of the Israeli-occupied West Bank and the Gaza Strip, and their leaders said Israeli annexation would violate international law and effectively nullify 1990 interim peace deals that included security cooperation.
Against the backdrop of Jordan's desert mountain range to the east, Palestinian farmers tended their crops and worried about their future in an area where the town of Jericho and the River Jordan are reminders of a biblical past.
"This is not Netanyahu's land to give," said Ismael Hassan, a Palestinian from the Jordan Valley village of Zbeidat, which sits 27 kilometers (17 miles) north of Jericho.
"Whether or not Netanyahu succeeds (in the election) we won't accept it. This land is for Palestine, for the Palestinians," Hassan, 75 said.
In Israel, which captured the West Bank in a 1967 war, Netanyahu's declaration was widely seen as a bid to siphon away support from far-right election rivals who have long advocated annexation of Jewish settlements in the territory.
Political commentators said Netanyahu had been emboldened to announce his plan by his close relationship with U.S. President Donald Trump, who has already recognised Israeli sovereignty over a strategic slice of occupied territory - the Golan Heights - that Israel annexed in 1981.
Some 53,000 Palestinians and around 12,800 Israeli settlers live in the part of the Jordan Valley that Netanyahu intends to annex, according to Peace Now, a settlement watchdog. The main Palestinian city in the region is Jericho, with around 28 villages and smaller Bedouin communities.
Palestinians often refer to the Jordan Valley as their "breadbasket". In his speech on Tuesday, Netanyahu described it as Israel's eastern border.
The valley, which at 2,400 sq km (926 sq miles) accounts for nearly 30% of the West Bank, has dozens of Palestinian farms as well as open areas which the Palestinian Authority has sought to develop for solar energy projects and industrial zones.
There are some 30 mainly agricultural Jewish settlements in the area, along with 18 smaller outposts, Peace Now says.
"It's impossible to have a Palestinian state without the Jordan Valley," chief Palestinian negotiator Saeb Erekat told Reuters in an interview from his office in Jericho.
"My prosperity can come (only) if I can control my natural resources, my shores on the Dead Sea, my shores on the Mediterranean, my water, my land," Erekat said.
Israel has long said it intends to maintain military control in the Jordan Valley, which abuts the Jordanian border, under any future peace accord with the Palestinians, and there is broad Israeli political consensus over the issue.
Erekat said the Palestinians would welcome "a third party presence" such as NATO or the European Union but said: "A Israeli military or civilian presence in the state of Palestine is not okay. Because this will not make peace."
The last round of Israeli-Palestinian peace talks broke down in 2014.
The Trump administration is expected to release its long-delayed peace plan after Israel's election, and it is still unclear whether it would adhere to previous U.S. support for the creation of a Palestinian state alongside a secure Israel.
Palestinians have boycotted the American efforts, citing what they call Washington's pro-Israel bias.
A U.S. official briefed on diplomatic contacts with Israel told Reuters the Trump administration was informed about Netanyahu's Jordan Valley statement ahead of time.
Asked whether the United States would support Netanyahu's planned annexation of the territory, a U.S. official told Reuters: "He's a politician making a political statement."
But the official added: "The prime minister made a very good political gambit that appeared based on statements that (U.S. Ambassador to Israel David Friedman) has already made."
A far-right coalition partner of Netanyahu hinted at doubt about the premier's sincerity, saying there had been no movement on the Jordan Valley question during his decade in power. "How come this matter (annexation) is coming up now, a week before the election?" Bezalel Smotrich told Israel's Army Radio.
Netanyahu also reaffirmed a pledge to annex all of the settlements Israel has established in the West Bank. But he said that broader step could take longer and required “maximum coordination” with Washington.
Netanyahu is fighting for his political life after an inconclusive election in April. His right-wing Likud party is running neck and neck in opinion polls with former armed forces chief Benny Gantz's Blue and White. (Reporting by Adel Abu Nimeh in Jiftlik, Rami Ayyub, Dan Williams and Jeffrey Heller in Jerusalem, Stephen Farrell in Jericho Writing by Rami Ayyub Editing by Jeffrey Heller and Mark Heinrich)