Barack Obama is going public to try to convince Americans that limited strikes against Syria are needed

President Barack Obama is going public to try to convince war-weary Americans that limited strikes against Syria are needed for the United States' long-term safety, while his national security team is attempting to reassure sceptical lawmakers that the US is not heading toward another Iraq or Afghanistan.

Obama on Monday planned to make his case for punishing Syrian President Bashar Assad for tuing chemical weapons against his own people - a charge Assad denies in a new interview. Top administration officials are heading to Capitol Hill for more classified briefings. And White House national security adviser Susan Rice is scheduled for a speech at a Washington think tank timed to the public relations blitz.

Obama will meet with Senate Democrats on Tuesday to seek support for U.S. military action against the govement of Syria, according to two Senate Democratic aides. The meeting at the Capitol would come just hours before Obama addresses the nation in a prime-time speech on Syria from the White House.

With Congress set to have its first votes authorising limited strikes into Syria as soon as Wednesday, Obama and his allies were arguing that the United States needs to remind hostile nations such as Iran and North Korea of American military might while working to reassure the nation that the lessons of the last decade were fresh in their minds.

"It is not Iraq, Afghanistan or Libya," White House chief of staff Denis McDonough said Sunday during one of his five network television interviews. "This is a very conceed, concentrated, limited effort that we can carry out and that can underscore and secure our interests."

White House Chief-of-Staff Denis McDonough speaks during an interview with Bob Schieffer on CBS's "Face the Nation" in Washington. Picture: AP

But McDonough conceded the administration lacks "irrefutable, beyond-a-reasonable-doubt evidence" that sceptical Americans, including lawmakers who will start voting on military action this week, are seeking.

"It's an uphill slog," said Rep. Mike Rogers, the Republican chairman of the House Intelligence Committee, who supports strikes on Assad.