WASHINGTON - The U.S. Democratic Party postponed its national presidential nominating convention from July to August on Thursday because of the uncertainty created by the ravaging coronavirus pandemic.

The quadrennial event, where Democratic activists are likely to nominate former Vice President Joe Biden to face Republican President Donald Trump in the November national election, had been scheduled for mid-July in Milwaukee, in the Midwestern state of Wisconsin, but now will start Aug. 17.

The party, in announcing the delay, said that even then the size and shape of the event is uncertain, with officials saying they will rely on the advice of medical and emergency responders about the coronavirus closer to the time of the event to protect the thousands of people who normally would attend the convention.

Every four years, the Democratic and Republican national presidential nominating conventions are a showcase of American democracy in action, even though for years the eventual outcome of the parties' presidential contests have been known for weeks ahead of the actual conventions. The conclaves have, however, served as rallies for the party faithful, with thousands of flag-waving political activists ready to cheer four days of speeches denouncing their opponents.

Joe Solmonese, chief executive of the Democratic National Convention Committee, said, "In our current climate of uncertainty, we believe the smartest approach is to take additional time to monitor how this situation unfolds so we can best position our party for a safe and successful convention."

He said that because "the scope and scale of the pandemic and its impact remain unknown, we will continue to monitor the situation."

Tom Perez, the Democrats' national chair, said, "Ultimately, the health and safety of our convention attendees and the people of Milwaukee is our top priority. And we will continue to be in contact with local, state, and federal health officials as we monitor this fluid situation."

He said Democrats are "ready to defeat Donald Trump, the American people are ready to elect a Democratic president, and I have absolute confidence that our team is ready to deliver a successful convention for our nominee."

In keeping an eye on the state of the pandemic closer to August, Democrats said they could adjust the convention's format, limit the crowd size and change the schedule.

With the new convention date for the Democrats, the two national parties will be staging back-to-back conventions in two successive weeks, which usually does not occur.

Republicans are slated to acclaim Trump's nomination for a second four-year term in the White House at their convention in Charlotte, in the Atlantic coastal state of North Carolina, starting Aug. 24.