The United States maintained pressure on Syria on Sunday, urging it to immediately and completely withdraw troops from Lebanon and warning that Washington would not tolerate "half measures".

Despite the announcement by Syrian President Bashar al-Assad ofa gradual pullout plan, White House counselor Dan Bartlett said onSunday that the United States and its allies would not stand by ifSyria fails to implement UN Security Council Resolution 1559, which calls for a complete withdrawal of foreign troops from Lebanon.

"We'll continue to make clear that they understand that the international community is not going to stand by and let Assad continue to have these type of half-measures, but to live up to his international demands," Bartlett said on "Fox News Sunday".

"The international community is united with the Lebanese peoplein asking and telling the Syrian government to withdraw its troopsand, more importantly, or just as importantly, withdrawing its security secret services as well from Lebanon," Bartlett said.

Assad told the parliament Saturday that Syrian troops would be initially pulled back to the Bekaa valley in eastern Lebanon and then to the Syrian-Lebanese border area. The move would put Syria in full compliance with international agreements and UN demands, Assad said.