The U.S. city of Denver has geared up the last-minute preparation as the Democratic National Convention kicks off Monday afternoon.
The biggest city in Colorado, nicknamed Mile High city, is to host nearly 5,000 Democratic officials and some 15,000 reporters during the four-day convention, from Aug. 25 to 28.
On the last day of the convention, Barack Obama will officially receive party nomination for presidential candidate and Senator Joe Biden of Delaware will receive nomination for the party's vice presidential candidate.

Speaker of the House Nancy Pelosi speaks at the 2008 Democratic National Convention in Denver, Colorado, Aug. 25, 2008. U.S. Senator Barack Obama [D-IL} is expected to accept the Democratic presidential nomination at the convention on Aug. 28. Hosting the 47th Convention carries a significant meaning to the city, which last hosted the event in 1908, exactly 100 years from now.
"It's the biggest event in the history of the city," Richard Grant, a Denver city spokesman told the media.
Thousands of policemen, special agents and secrete service staff have been deployed to guarantee the safety of the city.
Many roads to or around the main convention venues, Pepsi Center and the INVESCO Stadium, where Obama is to deliver his acceptance speech, were blocked for security reasons, resulting in traffic jam in the downtown area.
After doubling police forces, Colorado state government still had to seek help from the neighboring state of Wyoming.
The preparation committee has earlier vowed to present the mosteco-friendly convention ever, by means of building energy-efficient offices, running fuel-efficient transportation and encouraging reduction of carbon dioxide emission.
The city also rallies volunteer groups, named as the Green Team, to collect and appropriately dispose of waste produced by the convention activities.
"The 2008 Democratic National Convention is about the future," House Speaker Nancy Pelosi, a Democrat, told reporters. "That is why we are ensuring that this convention will be the greenest, most sustainable, most successful political convention in history."
The convention, originally instituted to choose the party's White House hopeful pair, has gone through dramatic changes since 1972. As the presumptive presidential and vice presidential candidates are decided ahead of the convention, it has become an occasion to officially ratify the nominees instead of choosing them.
However, Jenny Backus, Obama's convention advisor, said earlier that this convention will make the choice crystal clear between two very different approaches to leadership, referring to that of Obama and his Republican rival John McCain.
Source:Xinhua