As European foreign ministers met in Brussels on Tuesday to discuss tightening sanctions on Russia following the crash of a commercial airliner in the east of Ukraine, France said it could not cancel the delivery of the first of two helicopter carriers to the country.

President François Hollande did tell reporters in Paris he might be prepared to cancel the sale of a second Mistral warship if the European Union decided to expand its sanctions against Russia. “That will depend on Russia’s attitude,” he said.

But the Socialist Party leader, who is France’s least popular postwar president, cautioned that the first ship, named Vladivostok by the Russians, was already paid for and sanctions could not be applied retroactivity. The ship is on schedule to be delivered in October.

British prime minister David Cameron had earlier said it would be “unthinkable” for his country to fulfil such an order. The United States also urged France to reconsider the sale after pro-Russian militants from breakaway republics in the east of Ukraine apparently shot down a Malaysia Airlines jet last Thursday, killing almost three hundred passengers and crew. By far most passengers were Dutch; ten were British.

Although Russia has denied Western accusations that it backs the Ukrainian uprising, Russian weapons have found their way into country — possibly including the advanced missile launchers needed to intercept an airplane at high altitude. Ukraine’s military insists all of its missile launchers are accounted for.

Russian president Vladimir Putin has cast the blame solely on Ukraine, saying it “bears responsibility” for the plane crash.

Western countries imposed financial sanctions on Russia after it annexed Ukraine’s Crimean Peninsula in March. Several European countries, notably Germany, Italy and Spain, were seen as reluctant to threaten severing ties further, given their business relations with Russia. The European Union as a whole also gets roughly a third of its natural gas from the country, giving Putin significant leverage over his western neighbors.

At their meeting in Brussels, the ministers nevertheless raised the possibility of restricting Russian access to European capital markets, defense and energy technology, asking the executive European Commission to draft proposals this week. Several also called for an arms embargo although Germany’s Frank-Walter Steinmeier said such a ban would only apply to future contracts.

France’s €1.2 billion euro contract for the two Mistral ships — which can carry up to sixteen helicopters and sixty armored vehicles each — was signed by the government of Hollande’s conservative predecessor, Nicolas Sarkozy, in 2011. It was the first military hardware sale by a NATO country to Russia since the collapse of the Soviet Union in 1991 and had seemed to mark a normalization in East-West ties.

Those relations were deeply fractured earlier this year when Russia invaded Ukraine. It had objected to Ukraine entering into an association agreement with the European Union that would have made it impossible for the former Soviet republic to simultaneously join Russia’s customs union with Belarus and Kazakhstan. When the country’s relatively pro-Russian president, Viktor Yanukovich, budged to Russian pressure and pulled out of the European treaty at the last minute, mass demonstrations in the capital, Kiev, forced him to resign. The pro-Western leaders who took his place finalized the deal in June.