DUP candidates have agreed to sign a letter of resignation to be invoked if they breach party rules.
Mr Paisley said Sinn Fein "had to deliver"
A penalty for failing to comply with rules has been reduced from £20,000 to no more than £2,000.
The news came after an executive meeting on Thursday when the party ratified its election manifesto and its 46 candidates.
Protesters who picketed the meeting urged the party not to share power with Sinn Fein under any circumstances.
About two dozen demonstrators gathered outside an east Belfast hotel, as the DUP leadership arrived to unveil the election manifesto.
The demonstrators included victims' campaigner William Frazer, and Cedrick Wilson, a former Northern Ireland unionist assembly member.
Some of those present were carrying posters, one of which read "DUP/SF/IRA Collusion", another said "No DUP sell-out."
Some of the protestors vowed to stand against the DUP if the party fails to rule out power-sharing.
The manifesto will not be officially published for some days.
An election to the Northern Ireland Assembly will take place on on 7 March.
A new power-sharing executive is due to be formed on 26 March.
The transitional assembly has now been dissolved
However, DUP leader Ian Paisley told the BBC's Hearts and Minds programme on Thursday night he did not see "anything... about dates in this matter".
Asked if there were any circumstances he could foresee that would allow him to sit in a power-sharing executive with Sinn Fein on 26 March, Mr Paisley replied: "If Sinn Fein delivers".
He added: "We have made it clear we will listen to the IMC, we will also listen to the other agents of law enforcement and we will also take our own study of the situation on the ground.
"The dates are the governments, they have set down certain dates. I have done everything I need to do and can do under the (St Andrews) Agreement.
"There has been no real effort made by IRA/Sinn Fein to really forswear their violence. I am glad that the steps they have taken, they have taken them, but that is only the beginning."