Republican presidential candidate Mitt Romney assailed Barack Obama's foreign policy in a speech Monday saying the risk of conflict in the Middle East has grown under the U.S. president's leadership.

With his speech at the Virginia Military Institute, Romney hopes to undo a string of foreign policy stumbles, taking aim at an issue where polls show President Barack Obama holds a clear lead.

Saying there is, "a longing for American leadership in the Middle East," Romney called for the U.S. to take a more assertive role in Syria. He also wants new conditions on aid to Egypt and would impose tighter sanctions on Iran.

With the race growing tighter after Obama's poor performance in last week's presidential debate — the first of three — Democrats and Republicans now are looking to Thursday's debate confrontation between Vice-President Joe Biden and Wisconsin Rep. Paul Ryan.

And all in all both tickets are bearing down on their attempts to draw in the small percentage of voters who remain undecided in fewer than 10 states, with Iowa, Ohio, Virginia and Florida all set for candidate visits this week.

The U.S. president is not elected by the nationwide popular vote, but in a series of state-by-state contests.

Romney's campaign is working hard to chip away Obama's advantage among early voters, and there are signs the effort is paying off in North Carolina and Florida, two competitive states that the Republican nominee can ill afford to lose. Obama is doing better in Iowa, another battleground state important to both candidates.

Obama dominated early voting in key states four years ago, giving him a big advantage over Republican John McCain before Election Day even arrived.

President Barack Obama, accompanied by Cesar Chavez' widow, Helen F. Chavez, places a special Cesar Chavez red rose at his gravesite on Monday, in Keene, Calif. (Carolyn Kaster/Associated Press)

In an election-year display of incumbent's power, Obama on Monday declared a national monument at the home of Latino labour leader Cesar Chavez, the United Farmworkers Union founder who died in 1993. That is designed as an open appeal to Hispanic voters in swing states, before the president moves from Los Angeles to San Francisco for more fundraising.

Romney intended his foreign policy speech as a vehicle to send tough signals on Iran and Syria and portray Obama as weak for his administration's changing explanation for the deadly attacks on the U.S. consulate in Libya.

The Obama campaign was hit back in advance.

"We're not going to be lectured by someone who has been an unmitigated disaster on foreign policy," Obama campaign spokeswoman Jen Psaki said.

Voters give Obama higher marks than Romney on questions of national security and crisis response, but world affairs in general are a distant priority compared with the struggling U.S. economy, polling shows. Nevertheless, Romney's speech at Virginia Military Institute seeks to broaden his explanation of how he would serve as commander in chief.

After polls recently suggested Obama had narrow leads in several swing states, the Romney campaign says the race is tightening following his strong performance in last week's debate. To help maintain his momentum, Romney has tweaked his message over the last week, highlighting his compassionate side and centrist political positions.