By Francesca Landini and Lisa Jucca

MILAN (Reuters) - European Union foreign ministers considered on Friday the options for firmer action against Russia over the Ukraine crisis, discussing tougher sanctions but leaving any decision to their national leaders.

Ministers attending the informal meeting in Milan spoke of possibly toughening an arms embargo, extending the list of individuals or sectors targeted by economic sanctions and sending military equipment to Ukraine.

But diplomats said any new steps would only be taken by EU heads of state and government meeting in Brussels on Saturday.

"The Russians have crossed our red line many times and will go on until they are stopped," Lithuanian Foreign Minister Linas Linkevicius, who strongly backs tougher sanctions, told Reuters.

"Many ministers today have said that EU measures against Russia should be extended."

French Foreign Minister Laurent Fabius could not attend, but told France 24 television in Paris: "If Russia does not change its conduct, sanctions will probably be tightened even more."

Italian Foreign Minister Federica Mogherini, tipped to become the new EU foreign policy chief, said the ministers were looking for a long-term strategy to solve the Ukrainian crisis rather than a quick reaction.

SOLIDARITY WITH NEIGHBORS

The five-month conflict in Ukraine reached a dangerous point this week after NATO said on Thursday that well over 1,000 Russian troops had crossed the Ukrainian border and were fighting alongside pro-Moscow separatists.

Russia says it is not involved in the conflict pitting the rebels against the Ukrainian military, but EU foreign ministers were clearly not persuaded.

"We have to react, we should show solidarity to our neighbors," said Denmark's Martin Lidegaard as he entered the meeting chaired by Italy, the current EU president.

Dutch Prime Minister Mark Rutte, speaking from Amsterdam, said tougher sanctions against Russia should be considered.

The EU and the United States announced sanctions against Russia at the end of July, targeting its energy, banking and defense sectors. Previously the EU had only imposed sanctions against certain individuals and organizations accused of direct involvement in threatening Ukraine.

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Poland said Russian "aggression" had created the most serious security crisis in Europe for decades and German Foreign Minister Frank-Walter Steinmeier warned of a possible broader conflict between Russia and Ukraine.

"If the situation continues to worsen, finding a political situation becomes more and more difficult," he said.

Fighting in eastern Ukraine erupted in April, a month after Russia annexed Ukraine's Crimean peninsula in response to the toppling of a pro-Moscow president in Kiev.

A U.N. report this week said more than 2,200 people had been killed, not including the 298 who died when a Malaysian airliner was shot down over rebel-held territory in July.

(Editing by Tom Heneghan)