By Justyna Pawlak and David Brunnstrom
BRUSSELS, Jan 31 (Reuters) - The European Union and the United States slapped new sanctions on Belarus on Monday in response to a violent crackdown on protests after a disputed re-election of President Alexander Lukashenko in December.
Western governments, concerned over human rights violations in the ex-Soviet republic, have pressed Lukashenko to free scores of protesters held after the Dec. 19 vote, judged as fraudulent by the opposition and international monitors.
Lukashenko released seven detainees on Saturday, including a former presidential candidate, but kept others behind bars.
"We have seen practically no improvement on the ground. Our over-riding priority remains the release of all detainees," EU foreign policy chief Catherine Ashton told reporters after meeting EU foreign ministers in Brussels.
At the meeting, EU foreign ministers agreed to ban Lukashenko and about 150 officials from travelling to the bloc. They extended a list of people affected by an EU asset freeze to include those involved in the December crackdown.
The United States also expanded the number of Belarus officials covered by previous travel and financial restrictions and revoked temporary authorisation for business deals with the country's top petroleum and chemical conglomerate, Belneftekhim.
In Minsk, the foreign ministry said Belarus would take "proportional and effective measures" in retaliation -- possibly involving visa restrictions on officials from EU member states, a ministry source told Reuters.
Accusing the EU of interference in Belarus's internal affairs, ministry spokesman Andrei Savinikh said: "We call on the EU to step back from the logic of confrontation."
The EU had previously banned Lukashenko and other officials from travelling to the EU and froze their assets following disputed elections in 2004 and 2006, but had suspended the visa ban in 2008 to encourage reforms and reward Minsk for freeing political prisoners. It has imposed sanctions on Lukashenko intermittently during his 16-year rule.
Belarus is an important energy route for the EU and Lukashenko has taken advantage of the bloc's efforts to deepen ties with Minsk by manoeuvring between Russia and his western neighbours to win pledges of aid and investment.
But EU governments appeared ready to impose more financial restrictions on him, likely including a freeze on talks on financing reforms programmes, unless there was progress on human rights in Belarus, diplomats said.
At the same, the EU said it would give additional support to the country's civil society and victims of political violence, and expressed readiness to discuss liberalisation of visa rules for travellers from Belarus. (Additional reporting by Andrei Makhovsky in Minsk, Eva Dou in Brussels, Justyna Pawlak, David Brunnstrom and Richard Balmforth in Kiev; Editing Maria Golovnina)