The United States condemned Burma's military-led government on Monday for arresting pro-democracy activists over the weekend.
State Department spokesman Tom Casey demanded release of all political prisoners in Burma.
"By unjustly imprisoning organizers of peaceful demonstrations, Burma's ruling generals continue to blatantly disregard the international community's deep concern and calls for a halt to its crackdown," Casey said in a statement.
On Saturday, security forces arrested at least four prominent political activists who went into hiding to escape a government manhunt, Amnesty International said.
Casey said continuing repression makes "clear the need for the international community to maintain strong pressure on the Burmese regime."
Democratic US Senator Joseph Biden and Republican Senator Dick Lugar have sent a letter to Jose Manuel Barroso, the European Commission president, and Javier Solana, the EU foreign and security affairs chief, urging the EU to join the United States and implement targeted financial sanctions against members of Burma's junta.
"This moment of opportunity should not be lost. Let us do everything in our power together to help the Burmese people achieve the goal for which they have sacrificed so much," the senators wrote.
