That agreement assigns the British government the role of broker between Irish republicans and unionists, a role that Mr Adams said would be compromised if the government was in some way indebted politically to the DUP.
Northern Ireland's Democratic Unionist Party will not agree a deal to support Prime Minister Theresa May's Conservatives in government before the start of next week at the earliest, a DUP source said on Friday.
During previous talks processes, the smaller parties have claimed they have been marginalised.
Sinn Féin's Northern Ireland leader Michelle O'Neill said that on Brexit the Sinn Féin call for special designated status for Northern Ireland within the European Union was "building up traction" across Europe.
"The talks are still going on, but the one thing I am absolutely certain of is that the DUP don't want to see another election and Jeremy Corbyn in Downing Street", Grayling said. Would we then say they shouldn't be in government in the Republic?
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The former First Minister became the first political leader to meet Leo Varadkar in Government Buildings, in a 45-minute meeting.
"If we needed any reminder of the urgency of having power-sharing institutions in Stormont, it is the coincidence of the Brexit negotiations beginning in Brussels today".
"I've got serious members in my constituency texting me saying: 'You've got to get rid of her quickly because every time she appears she's making the party more toxic, '" the MP told the newspaper.
However, James Warren, a forecaster at the National Institute of Economic and Social Research, said growing uncertainty makes investors less willing to plough their money into the British economy.
Ministers have already said the Queen's Speech may have to be put back from its scheduled date of Monday because of the ongoing negotiations.
On Friday, Ms Foster signalled her optimism that a deal to restore powersharing by a June 29 deadline could be done, adding that it "takes two to tango and we're ready to dance".