Fine Gael has said it is "preparing to go into opposition" following its poor showing in the Republic of Ireland's general election.
The party, which has been in power for the past nine years, finished third behind Fianna Fáil and Sinn Féin, losing 12 seats.
Its parliamentary party met for six hours on Monday, the first time it had done so since the election.
Leader Leo Varadkar said he accepted responsibility for the campaign.
He said Sinn Féin has the largest party (in terms of share of the vote) and that the onus was on it to form a government and deliver on the "extraordinary promises" it made during the election.
Mr Varadkar said if Sinn Féin fails to form a government, then the onus passes to Fianna Fáil.
He said his future is about leading the party into opposition.
A statement from Fine Gael said that Mr Varadkar "relishes the challenge to lead a strong and effective opposition for the benefit of the country".
It added: "There will be no negotiations on a programme for government without a further mandate from the parliamentary party", which will meet again next week.
Earlier, Sinn Féin leader Mary Lou McDonald said her party remains determined that what she called an "alternative and new government of change" can be created.
Ms McDonald said talks would continue this week and the party would intensify conversations with other parties and independents.
She said there was a left-wing block and they needed to figure out if they could rule from a minority position.
She said "people had voted for the party to be in government" and she described the idea of Fianna Fáil and Fine Gael being returned as "unthinkable".