Fritz Longchamp, chief of staff to Rene Preval, the president, said some protesters were trying to break down the palace gates before the UN troops moved to establish a security perimeter around the building.
Jean-Jacques Augustin, a Haitian photographer, was hit by a rubber bullet after scuffles broke out between UN peacekeepers and demonstrators, one of his colleagues said.
At least five people have died in Haiti since protests over the doubling of prices for foodstuffs such as rice began last Wednesday.
The 15-member council issued its statement backing the government in Port-au-Prince and the 10,000-strong UN force in Haiti (MINUSTAH) after hearing a briefing from the Hedi Annabi, UN special envoy to the country.
|"Living conditions are horrible. |
We are tired
of hearing promises,
"The members of the Security Council reiterated their sustained support to the government of Haiti and MINUSTAH in their efforts toward ensuring stability, consolidating democracy and sustaining conditions conducive to economic growth, social development and delivery of humanitarian assistance," a statement said.
Annabi told the council that the current unrest appeared "to have a political dimension, in addition to expressing mounting frustration about the rising cost of basic food commodities".
He later told reporters that there was a need "for urgent assistance to alleviate the suffering of the population".
Haiti, home to 8.5 million people, is the poorest country in the Americas.
Eighty per cent of its population earns less than $2 a day, below the UN-established poverty rate.
"Living conditions are horrible. We are tired of hearing promises, we want fast action," Wilson, one of the protesters outside the presidential palace, told the AFP news agency.
The protests began after a sudden jump in prices for fuel and basic food commodities.
The rice price has doubled from $35 to $70 for a 120 pound sack, and gasoline has seen its third price hike in less than two months.
Jacques-Edouard Alexis, Haiti's prime minister, condemned the protests but acknowledged the source of the discontent.
On Monday he announced a $42 million programme to ease the situation, including the creation of thousands of jobs for youth, grants for small businesses, and other measures to solve the problems.
"These measures take time. We need to have patience," he said on local radio.