VILNIUS, Feb. 23 (Xinhua) -- Britain's withdrawal from the EU will pose a significant challenge to the European budget after 2020, Lithuanian President Dalia Grybauskaite said Friday.

"Negotiations on the budget currently are in their initial phase. Obviously, there is a wish to finish them before the European Parliament's election in 2019. However, usually the accord is reached moments before the new financial long-term perspective comes into force," Grybauskaite said in an interview with local radio broadcaster Lietuvos Radijas.

Grybauskaite was speaking before attending an informal European Council meeting in Brussels where the political priorities of the EU's new long-term budget are being discussed on Friday.

Given the additional needs and challenges facing the EU, such as defense and migration, the negotiations could draw out until spring 2020, said the president.

With the United Kingdom out of the EU, the annual budget financing may be short of 13 billion euros (16 billion U.S. dollars), Grybauskaite noted.

"EU member states will have to decide how to provide sufficient funding to ongoing programs and to future priority projects," she said.

Earlier this month, Grybauskaite presented the Baltic country's expectations for the long-term EU budget to European Commission President Jean-Claude Juncker, and President of the European Council Donald Tusk, who were on a visit to Lithuania.