Israeli Prime Minister Benjamin Netanyahu has dismissed US calls for a West Bank settlement freeze as unreasonable.
The claim comes as Jewish settlersattacked Palestinian labourers and set fire to agricultural land in the West Bank.
Israeli officials say Netanyahu delivered his assessment to a closed parliamentary committee today.
The US has demanded that Israel halt all construction in the settlements. Netanyahu says some building must continue to accommodate what he calls "natural growth."
A meeting participant says Netanyahu testified that Israel cannot "freeze life" in existing settlements. He said "there are reasonable requests and unreasonable requests."
Another participant says Netanyahu said his job is to protect Israel, even if his decisions are not popular.
The participants spoke on condition of anonymity because the meeting was closed.
Earlier, mobs of Jewish settlers went on a rampage in the West Bank, attacking Palestinian labourers and setting fire to agricultural land to protest against an Israeli government crackdown on unauthorised outposts in the territory.
Six Palestinian labourers travelling in a minivan were injured when stone-throwing settlers attacked them, the workers said.
The violence comes as President Obama's administration is pressuring Israel to honour long-standing pledges to tear down wildcat settlement outposts in the West Bank and to freeze expansion in existing, government-sanctioned settlements.
Prime Minister Benjamin Netanyahu has balked at the US demand to halt construction in existing settlements and faces stiff resistance within his hard-line government against taking down about two dozen of the outposts. The disagreement has caused a rift between the allies.
Today's violence was all deep inside the West Bank, where most of the hard-line settlements are located.
It started overnight near the radical settlement of Yizhar, police spokesman Micky Rosenfeld said. About 100 settlers blocked a road to protest against Israel's recent removal of a handful of tiny, uninhabited outposts. Six settlers were later arrested there.
Before dawn near another radical settlement, Kedumim, stone-throwing settlers ambushed a minivan carrying Palestinian labourers to Israel, the workers said. Six of the 15 Palestinians on board were hurt, including Yahye Sadah, who was hit in the head.
"I was hit in the head by a rock from a distance of 3 meters (10 feet). I ran away. I thought I'd die," said Sadah, 44, who spoke from a nearby hospital after getting six stitches.
Police said settlers threw rocks and burned tires in the area but that only one man was slightly wounded. The attackers fled and no arrests were made, they said.
A few hours later, settlers torched a wooded hilltop near Nablus and set trees and Palestinian agricultural land on fire near the village of Hawara, local council chief Ali Eid said.
Romel Sweiti, a Hawara resident, said the fires torched nearly 1 acre (0.40 hectares) of land. He said about 50 teenage Israeli settler girls gathered on a main road and blocked traffic as Israeli paramilitary police stood in the background.
Nearly 300,000 Israelis live in the settlements among 2.4 million Palestinians in the West Bank. Another 180,000 live in Jewish neighborhoods of east Jerusalem. The Palestinians claim both areas - captured by Israel in the 1967 Mideast war - as parts of a future independent state.
The US considers the settlements an obstacle to peace, but traditionally has done little on the issue, a policy that appears to be changing under President Barack Obama.