EU leaders are expected to discuss the economic situation in Russia when they meet on Thursday in Brussels - focusing on the Ukraine crisis, EU sanctions and the plummeting ruble.

The Russian ruble has lost more than 50 percent of its value this year, driven down by dropping oil prices as Moscow also deals with international sanctions over the Ukraine conflict.

Their meeting will come shortly after Russian President Vladimir Putin gives an annual press conference to journalists.

"We could be saying the sanctions work, but we are not rejoicing," conservative German EU parliamentarian Manfred Weber said on Wednesday.

"We hope the developments will make it clear to Russian President Vladimir Putin ... that the path Moscow is on is the wrong path."

Western nations have repeatedly accused Russia of involvement in the Ukraine crisis, by supplying weapons and troops to the separatist rebels. Russia denies these claims. The conflict has killed at least 4,700 people.

Merkel: sanctions to stay

Ahead of the talks, German Chancellor said that the Moscow sanctions had to remain in place.

Speaking to lawmakers at the Bundestag, Merkel said Europe could not allow Russia to violate the principles of the rule of law, respect and partnership.

"As long as this goal is not achieved, the sanctions will stay," Merkel said. She added the EU wanted to work together with Russia and not act against it. Merkel did not address Russia's monetary and economic troubles.

EU investment

Also up for discussion on Thursday in Brussels is European Commission president Jean-Claude Juncker's investment plan to revive the EU economy - a 315-billion-euro ($380 billion) proposal to help boost growth and jobs.

It's expected the leaders will back the general concept of the plan, but leave disagreements on the finer deals until later. The commission will flesh out the plan with legislative proposals next year.

The plan aims to boost private investment, which plummeted during the bloc's economic crisis. Juncker has urged nations to allocate more from their budgets in getting the plan off the ground.

"Several states have shown potential interest," Juncker said in a debate at the European Parliament.

"I now wait for concrete proposals and not just 'talk-talk.' I need 'money-money,' hard cash now," he said.

The summit will be led for the first time by new European Council president, and former Polish Prime Minister Donald Tusk.

"We will provide a clear direction for work in the coming months," Tusk wrote in his invitation letter to the leaders.

Also expected to be discussed is the Ebola outbreak in West Africa, for which the EU member states have so far contributed over 1.1 billion euros.

jr/mg (AFP, dpa)