President George W. Bush has threatened further sanctions against Burma's military rulers over their crackdown on protests.
"We have sanctioned individuals within Burma and are considering additional sanctions," Mr Bush said. "But sanctions don't mean anything if we're the only sanctioner."
Washington imposed new sanctions last month on senior Burma military officials, toughening US measures that had been in place for years but had forced little change. The United States has been pressing for stronger UN action.
European Union foreign ministers agreed yesterday to strengthen sanctions against Burma's junta and warned they could ban all new investment.
Two weeks ago, pro-democracy protests in Burma were crushed by the Asian nation's military leaders. Many protesters were arrested, and some killed, and police are still raiding homes and arresting activists.
Suggesting growing impatience with the international response to Burma, Mr Bush said: "Sometimes international bodies are non-consequential. That is, they're good talking, but there's not a consequence. At some point there has to be consequences."
Asked what was needed to bring freedom and democracy to Burma, after 45 years of military rule, Bush said, "Enormous international pressure to make it clear to the generals that they will be completely isolated and not accepted into the international community of nations."
The UN special envoy to Burma, Ibrahim Gambari, is in southeast Asia as well as China and India this week trying to build support for a united diplomatic approach to Burma.