Building starts on settler homes in the Israeli-occupied West Bank hit a seven-year high in the first quarter of 2013, Israeli watchdog Peace Now said on Sunday.
"Between January 2013 and March 2013, construction of 865 new housing units began," the NGO said in a statement quoting recently released government statistics.
"This is three times as many construction starts compared to the same quarter last year (January-March 2012)," it added. "If compared to the final quarter of last year (October-December 2012), this is an astonishing 355 percent increase."
The Peace Now report comes as US Secretary of State John Kerry, who last week warned time was running out for a possible peace deal, is expected to return to Israel and the Palestinian territories within days.
It will be Kerry's fifth visit since taking office in February, as he seeks to revive direct Israeli-Palestinian peace negotiations after a nearly three-year hiatus.
Palestinians say they will resume talks only if Israel stops building on land it wants for a future state and if it agrees to negotiate on the basis of the borders which existed before the 1967 Middle East war when the Jewish state seized the West Bank and Gaza.
Israel demands talks "without preconditions" and refuses publicly to freeze settlement building.
"Any government committed to peace would not allow, nor continue, to build settlements that inevitably harm the chances for peace," Peace Now said.
"These findings provide further evidence of a continuing government policy to prioritise settlement expansion."