The Irish government must make clear to the UK government that direct rule is not an option if talks to restore powersharing in Northern Ireland fail, Gerry Adams has warned.
The Sinn Fein president said another snap Assembly election was the only way to proceed if negotiations do not deliver agreement.
Northern Ireland Secretary James Brokenshire has said he will either trigger an election or move to a return to Westminster decision-making if there is no deal by "early May".
Last month, Taoiseach Enda Kenny said he and Prime Minister Theresa May shared the position that direct rule was not an option.
But with Northern Ireland approaching seven weeks without a devolved government following March's election, it appears that option is now very much on the table in Downing Street.
Current legislation dictates Mr Brokenshire should call another a poll if negotiations to form an administration fail.
The Government lost its power to suspend devolution and reintroduce direct rule in the 2006 St Andrews Agreement.
It would require emergency legislation in Westminster for Mr Brokenshire to regain that authority.
Addressing an Easter Rising commemoration in Co Tyrone, Mr Adams said: "Sinn Fein wants a deal.
"But if there is no deal then there has to be an election.
"The role and responsibility of the Irish government must be to assert that an election is the only legal course open to the British government, if the current talks fail to elect an Executive."
Negotiations to save devolution remain log-jammed, with two deadlines to form a new ruling executive falling by the wayside.
Sinn Fein demands for legislative protections for Irish speakers, an end to the region's ban on gay marriage and the implementation of a Northern Ireland-specific bill of rights are among the issues of dispute.
Talks will reconvene after Easter, working to the new early May deadline.
Sinn Fein has accused the DUP of preventing the formation of a "rights-based" government.
The DUP has claimed Sinn Fein is focused only on the demands of its own supporters, and is failing to appreciate that others want movement on other issues.
The main unionist party hinted at a shift in approach to the Irish language last week when party leader Arlene Foster, who previously insisted she would never support an Irish Language Act, pledged to meet Gaelic speakers to hear their concerns.
While Sinn Fein welcomed her comments as a "positive step", Mr Adams insisted the DUP had to go further.
"Arlene Foster needs to reflect over this Easter time on whether she wants to reinforce unionist separation, segregation, from the rest of us or whether she seizes the opportunity to bring unionism in a new direction to respect diversity and end division," he said at the commemoration in Carrickmore.
"The alternative will not work."
The DUP is seeking to secure protections for Ulster Scots speakers and have also pressed for the introduction of a military covenant in Northern Ireland, a series of policies that define the state's obligations to its armed services.
Mr Adams said seeking a "counter balance" represented a "flawed approach".
"The DUP leader can cast about for some 'counter balance', some quid pro quo, to legitimate progressive measures which benefit everyone," he said.
"She will achieve absolutely nothing but continued division if she thinks she can build a strategy on such a flawed approach."
Ahead of the Easter weekend, DUP MP Gregory Campbell urged Sinn Fein to rethink its approach to negotiation.
Mr Campbell told republicans they need to look beyond their own wish list.
"Sinn Fein's closed-mind approach has led to Stormont being closed, it needs to change," he said.
"The current impasse was created when Sinn Fein walked out of Stormont.
"Critical public services suffer whilst the deadlock is maintained through their refusal to re-establish the executive. The DUP is prepared to establish the executive and work through the range of problems people from across Northern Ireland face."
He added: "The Easter break offers them (Sinn Fein) the opportunity to refocus on issues which they have to get their collective heads around.
"That can be of benefit but only if they use the opportunity and come back to begin looking at the issues which people beyond Sinn Fein's closed circle want to get resolved."
Devolution first crashed in January when Sinn Fein pulled the plug on the last executive over a row about a botched green energy scheme, triggering last month's snap election.