The European Union has imposed an import embargo on timber, gems and precious metals from Burma in response to the military government's crackdown on demonstrators.
In a statement released after Monday meeting in Luxembourg, European foreign ministers said the seriousness of the situation in Burma has made it necessary to increase direct pressure on its military rulers. They said the new measures are designed to target those responsible for the violent crackdown and will not harm the general population.
Today's measures strengthen existing EU sanctions on Burma's leadership, which include visa bans and asset freezes.
Britain's Foreign Secretary David Miliband said the EU would offer economic incentives and support if Burma participates in a U.N.-brokered dialogue with its opponents. But he threatened further sanctions if Burma's government refuses to cooperate.
U.S. President George Bush said enormous international pressure was needed to make it clear to Burma's ruling generals that they will be completely isolated.
A spokesman for the U.S. State Department said continuing arrests contradicted the Burmese government's claims it was open to dialogue. Spokesman Tom Casey said the crackdown was, in his words, "a funny way of showing that you care."
Earlier, British Prime Minister Gordon Brown and U.N. special envoy Ibrahim Gambari issued separate statements calling for Burma to halt its crackdown.
Also Monday, Thai Prime Minister Surayud Chulanont asked visiting Gambari to help broker regional talks on Burma's political crisis.
The U.N. envoy is set to return to Burma in mid-November, but Mr. Surayud said he would send a letter to the military government asking that Gambari be allowed to visit sooner.
Burmese authorities opened fire on thousands of anti-government demonstrators in Rangoon last month. Since then, authorities have arrested thousands of monks and activists, and many are believed to have been killed.
Information for this report is provided by AP and REUTERS.