Brexit is set to cause a "very challenging" shortfall in the EU's budget, German Chancellor Angela Merkel said on Monday ahead of meetings with the prime ministers of Luxembourg and the Netherlands in Berlin.

Britain's departure from the bloc will leave an estimated €12 billion ($15 billion) annual shortfall in the 2021-2027 EU budget. Merkel's admission comes a week after the EU's budget commissioner, Günther Oettinger, said he expected Germany to pay at least €3 billion more annually to the bloc.

Read more: Juncker: EU member states must contribute more post-Brexit

Bridging the budget after Brexit:

• Merkel said the need to finance EU defense and migration projects also made it more difficult for the remaining 27 member states to plug the Brexit hole. The chancellor also said "not all countries can pay more."
• Merkel later met separately with Luxembourg Prime Minister Xavier Bettel and Dutch Prime Minister Mark Rutte to discuss the challenge.
• Rutte's government has reportedly told the EU Commission it will not pay more into the budget after Britain leaves in 2019, German daily newspaper Sueddeutsche Zeitung reported on Monday citing an internal Dutch government paper.
• Oettinger, a German politician from Merkel's center-right Christian Democrats (CDU), had said on Friday that Germany should make up €3-3.5 billion of the resulting shortfall. "That would be about 10 cents per day more than now per head," he said.

Read more: Germany's EU bill to rise by 16 percent post-Brexit: report

German finance minister weighs in: In Brussels, acting German Finance Minister Peter Altmeier said after a meeting with EU finance ministers on Monday he could not say whether Germany would pay more into EU coffers. That, he said, would only be possible after a new government had been formed in Berlin.

Read more: EU budget: Be nice or you won't get your allowance!

Germany open to paying: Merkel's conservatives and the Social Democrats (SPD) have said they are willing to increase Germany's contribution in a recently agreed coalition agreement. But party leaders are yet to name a figure. SPD members are currently voting on whether to accept the coalition agreement.

What happens next: EU leaders are set discuss the bloc's future finances at a summit in Brussels on Friday. The Netherlands is reportedly not the only EU member that opposes paying more. Officials from Sweden, Austria, Finland and Denmark have reportedly also said they will not foot a higher annual bill.DW's editors send out a selection of the day's hard news and quality feature journalism. You can sign up to receive it directly here.

amp/aw (dpa, AFP)