US President Barack Obama has warned the Palestinian government of Mahmoud Abbas that 'there will be consequences' if he declines to open direct talks with Israel, Arab media reported Saturday.

'It is time to go to direct negotiations,' Obama said in a letter sent to Abbas and published Saturday by the London-based newspaper al-Hayat.

The US 'will not accept a rejection of (Obama's) proposal to go to direct negotiations' and 'there will be consequences to this rejection in the form of lack of confidence in Abbas and the Palestinians, which can have further impact on US-Palestinian relations,' the letter continued.

Hanan Ashrawi, a Palestinian member of the Revolutionary Council, had claimed in an interview with the London-published Arab newspaper al-Quds al Arabi Saturday that there had been 'threats to isolate the Palestinians and cut off relations' made by the US as part of the 'huge pressure on the Palestinian Authority to move to direct talks.'

But a White House source rejected that claim as 'not true' Saturday, the Israeli daily Haaretz reported.

The US expressed its hope in the letter published by al-Hayat that direct negotiations would start at 'the beginning of next month.'

Obama would help the Palestinians get their own state if they enter direct negotiations, but will not offer any assistance if they refuse, the letter said.

The US administration also rejected the option of going to the United Nations as an alternative to direct negotiations.

The four months allocated to the US-mediated indirect 'proximity' talks will end in September, as will a partial 10-month moratorium on Israeli construction in the West Bank.

The Israeli government, the US and the European Union have all expressed their desire that direct talks get under way 'immediately'.

The Arab League Thursday also gave its green light, but called on the US administration to accept negotiations defined by a clear timeframe, specific reference terms and a monitoring mechanism.

The Palestinian government has so far insisted on seeing some 'progress' from the Israeli side before moving to direct talks.