EU foreign ministers have agreed to impose tough new sanctions on Iranian industries to try to pressure Tehran into negotiating an end to its sensitive nuclear activities.

After meeting in Luxembourg on Monday, the top diplomats of the 27-nation bloc released a statement saying the tougher sanctions are in response to what they call Iran’s “flagrant violation” of international obligations and refusal to fully cooperate with the U.N. nuclear agency.

EU foreign policy chief Catherine Ashton said the sanctions are meant to persuade Iran to engage in negotiations that address international concerns about suspected military dimensions to the Iranian nuclear program. Tehran denies Western accusations that it is trying to develop nuclear weapons under cover of a civilian energy program.

The EU statement said one of the new penalties is a general ban on financial transactions with Iranian banks unless the transfers deal with humanitarian goods and EU authorities approve them in advance. Other measures include tighter restrictions on dealings with Iran’s central bank, a ban on importing Iranian natural gas, and a ban on exporting graphite and metals that Iran could use for its weapons programs.

The White House welcomed the EU move, saying it “strengthens international efforts to … isolate the Iranian government.” Spokesman Jay Carney also said “rallying the world to increase the pressure on (Iranian leaders) so that they stop pursuing a nuclear weapon has been a top priority” for President Barack Obama.

Under the new sanctions, EU companies are prohibited from supporting Iran’s ship-building industry and banned from transporting or storing Iranian crude oil – the country’s main source of revenue. The EU banned imports of Iranian oil earlier this year.

An EU asset freeze and travel ban also will be imposed on additional entities whose names will be published Tuesday.

British Foreign Secretary William Hague said the EU will continue to intensify pressure on Iran “over the coming months” unless intermittent negotiations between world powers and the Islamic republic succeed. German Foreign Minister Guide Westerwelle accused Iran of “playing for time” and said EU nations do not see a “sufficient” Iranian readiness for “substantial” nuclear talks.

Iran has engaged in three rounds of talks with the five permanent members of the U.N. Security Council plus Germany since April, but has refused to scale back uranium enrichment unless major international sanctions are lifted.