Bush's keynote speech branded Syria an "oppressive neighbour" to Lebanon and insisted Damascus "end its occupation" there.
EU foreign ministers separately underlined their support for a UN resolution calling on Syria to withdraw its troops.
Syria's expatriate affairs minister Buthaina Shaban said Bush's statement was part of a plot to reshape the region.
"What has happened in Lebanon is an inseparable part of the plan to restructure the Middle East. This causes real worries to the people of this region," Shaban told Aljazeera.
The United States and the European Union demanded the immediate application of a UN resolution calling for the withdrawal of Syrian troops from Lebanon, Luxembourg Prime Minister Jean-Claude Juncker said on Tuesday.
Juncker (R) is calling for a UN
resolution to be applied to Syria
"We spoke about the Middle East and especially Lebanon ... to vigorously condemn against the attack which claimed the life of former prime minister [Rafiq al-Hariri], to demand respect for the [UN] Security Council resolution and its immediate application," he said.
Juncker, whose nation holds the rotating EU presidency, was speaking during a joint news conference with Bush after the EU-US summit.
A group of Syrian scholars, among them opposition figures, called for a cooling-down period for Lebanese-Syrian relations.
Michel Kilo, one of the scholars who signed the statement, told Aljazeera: "An atmosphere is being created in this region that takes us to an all-out stand-off, particularly in Lebanon.
"An atmosphere is being created in this region that takes us to an all-out stand-off, particularly in Lebanon"
Michel Kilo, Syrian scholar
"Such a development will lead to the isolation of our country and placing it before a challenge which it could not be able to counter."
Kilo said the Syrian government was considering the implementation of the Taif accord.
Kilo's group supports the accord, which calls for Syrian troops to be redeployed to the Bekaa Valley as a first step to an eventual withdrawal, but with no timetable.
UN resolution 1559 calls for all foreign forces to be withdrawn from Lebanon and for resistance groups such as Hizb Allah to be dissolved.
Syria maintains about 14,000 troops in Lebanon but has been facing growing pressure to pull out after al-Hariri's assassination on 14 February.