Chancellor Angela Merkel's efforts to forge a three-way ruling coalition could last all weekend after the parties missed Merkel's Thursday deadline and failed to reach agreement on key issues such as migration and finances.

Merkel's conservatives, the pro-business Free Democrats (FDP) and the environmentalist Greens had told reporters around 4 a.m. local that they were taking a break after 15 hours of frustrating negotiations and would resume their work around midday Friday.

Wolfgang Kubicki, deputy leader of the FDP, told reporters he was "extremely frustrated" after four weeks of negotiations that have failed to produce agreement, Reuters reported.

"If things stay like this, we won't get any further," Kubicki said. "It's frustrating when you sit together and then you realize that you're right back where you started."

Kubicki told ARD television the parties were "still so far apart on key issues such as immigration, fighting climate change, finances and domestic security, that I can't imagine how we can get together in the short time available."

Michael Kellner, a top official with the Greens, said there was much to be done yet. "Nothing is agreed, nothing has been decided," he said.

Fellow Greens negotiator Juergen Trittin told broadcaster DLF the sides had moved closer on the issue of phasing out coal production, but the Bavarian conservative party refused to compromise on the issue of asylum seekers who wanted to bring their immediate families to Germany.

Failure to reach agreement on a "Jamaica" coalition, so named because the parties' colors match those of the Caribbean island's flag, could lead to new elections.

That is a scenario none of the negotiating parties wants, given predictions that the Eurosceptic Alternative for Germany (AfD) could make further gains after surging into parliament in the Sept. 24 national vote. A new election could also weigh heavily on the Euro.

For Merkel, eyeing a fourth term, the stakes couldn't be higher. "If the conservatives, the Greens and the FDP can't pull together, there's no way to avoid new elections," Der Spiegel news weekly wrote, as reported by AFP. The potential tie-up is untested at the national level and questions abound as to how stable such a government would be. "It's not just the chancellor's fourth term that depends on the success of Jamaica, but her entire political career," the best-selling Bild newspaper said.

Merkel could still reach out to her previous coalition partners, the Social Democrats (SPD), but they have vowed to remain in opposition after suffering their worst election result since 1933 in the September elections.

The chancellor is under pressure from her own conservative bloc, particularly the Bavarian CSU sister party, to hold the line on key issues in the talks, especially on immigration after the influx of some 2 immigrants, both legitimate and illegitimate, over the past two years.

Despite being the party of the Chancellor who initiated this chaos, the CSU, worried about losing further ground in a 2018 state election, is pushing for immigration caps and more order in the process.

If negotiators agree to a deal, it must still pass muster with lower-ranking party officials. A key test would be a Greens conference on Nov. 25, when the party's rank and file would examine any coalition pact.