Israel's hard-line foreign minister said his party would try to block any extension of Israel's settlement slowdown, a move that could derail the Middle East peace negotiations.
Avigdor Lieberman said the Israeli government must keep its explicit promise to voters that the 10-month slowdown, declared under US pressure to draw the Palestinians to the negotiating table, will end as scheduled at the end of September.
The September 26 deadline is a challenge for the fragile talks launched in Washington last week. The Palestinians say they will quit the talks if the slowdown ends, but extending it could potentially bring down the Israeli government.
Israeli prime minister Benjamin Netanyahu has yet to say how he will handle the deadline.
"A promise is a promise," Mr Lieberman told Israel Radio. "We will not agree to any extension. I promise that if there's a proposal that we don't accept it will not pass," he added.
Mr Lieberman's Yisrael Beitenu party is a key member of Israel's governing coalition, which is led by Mr Netanyahu's Likud party.
In a sign that compromise was possible, however, Mr Lieberman told the daily Yediot Ahronot that he would not quit the coalition even if he does not get his way.
"We will not leave or bring down the government. We will fight from the inside for what we believe," he told the paper.
Mr Lieberman told Army Radio the new talks were creating too many expectations and that the declared goal of a peace deal within a year was impossible.
Mr Netanyahu is due to meet Palestinian president Mahmoud Abbas for a second round of talks next week in Egypt and Jerusalem. US Secretary of State Hillary Clinton is also scheduled to attend.