Efrem Lukatsky, Associated Press
A masked pro-Russian activist places a self-proclaimed 'Donetsk Republic' flag over the office of a "Privatbank" bank, owned by a businessman who is considered to back the new pro-western government in Donetsk, Ukraine, Monday, April 28, 2014. Ukraine's acting government and the West have accused Russia of orchestrating the unrest, which they fear Moscow could use as a pretext for an invasion.

BRUSSELS — The European Union on Monday added 15 more officials to its Russian sanctions list to protest Moscow's meddling in Ukraine, diplomats said.

Ambassadors of the EU's 28 nations agreed at a meeting in Brussels to broaden the bloc's travel ban and asset freeze sanctions, three diplomats separately confirmed to The Associated Press. They spoke only on condition of anonymity pending an official announcement.

Two diplomats also said the ambassadors will meet again Wednesday and could add more names.

Monday's decision still requires official approval from the EU's governments but officials said that is merely a formality and is expected within the coming hours.

The names of the individuals targeted weren't immediately released but would be included in the official publication of the move in the bloc's legal journal early Tuesday.

The decision brings the total number of Russians or pro-Russian individuals in Ukraine targeted by the EU's sanctions to 48.

The initial sanctions were adopted following Russia's annexation of Ukraine's Crimean Peninsula last month. The EU and the U.S. now also accuse Russia of destabilizing eastern Ukraine. NATO says Moscow has amassed some 40,000 troops just across the Ukrainian border and could invade the country within days if it wanted to.

The EU move comes after the U.S. decided to broaden its own sanctions to include seven Russian government officials and 17 companies with links to President Vladimir Putin.

The EU is Russia's biggest trading partner, giving it greater economic leverage over Moscow than the U.S. However, the EU treads more carefully in imposing sanctions since Russia is also one of its biggest oil and gas suppliers — and the bloc apparently shied away from following Washington's lead in targeting specific Russian companies.

EU leaders have threatened Russia with tougher economic sanctions, for example targeting its financial industry or the energy sector, in case the situation in eastern Ukraine further escalates, but those sanctions are not yet being considered, EU officials said.

Follow Juergen Baetz on Twitter at http://www.twitter.com/jbaetz