WASHINGTON - US presidential nominees Donald Trump and Hillary Clinton are expected to face off over foreign policy on Wednesday, when the two meet in their third and final debate. The Republican nominee will be attempting to reverse his standing in an election that appears to be tilting away from him.In a publicity stunt which may yet backfire, Trump has invited President Barack Obama's half-brother Malik to attend the debate.the Kenyan-born convert to Islam giving his backing to the billionaire in July to "Make America great again", however his past may come back to haunt Trump's pro-Israel credentials.Malik has been photographed wearing a Palestinian scarf bearing Hamas slogans, with the image re-appearing on social media after Trump's campaign announced his invitation to the debate. Trump's campaign manager Kellyanne Conway came under fire from hundreds of Twitter users on Wednesday evening after posting a picture of her "hanging out" with Malik Obama. "Did you ask him about Hamas?" was a common response to her tweet. If and when Israel comes up during the debate at the University of Las Vegas, Nevada, it remains to be seen if Clinton will use this to her advantage, while Trump is certain to follow up on his previous criticism of the Iran deal, which the Democratic nominee has stood by.A Twitter List by Jerusalem_Post "This one is important if Trump is going to have any chance to get back into this race," said Republican strategist Charlie Black. "He's going to have to talk about issues effectively and not get down in the mud, and he needs to talk about jobs." For Clinton, who leads national opinion polls and leads in most of the battleground states where the Nov. 8 election is likely to be decided, the 90-minute debate offers her a chance to make her closing argument on why she is the best suited to succeed President Barack Obama."It's hard to imagine at this point anything that could happen in this debate that could change the overall dynamic of this race," said Democratic strategist Steve Elmendorf. "I can't imagine what Donald Trump could do positively or a mistake Hillary Clinton could make to change the trajectory of this race."In a campaign that has been more about character than policy differences, both candidates enter the debate ring a bit wounded from recent events.Trump has spent the past week denying and defending himself from charges that he groped women. Clinton has struggled to get past a flap over her handling of classified emails while US secretary of state from 2009 to 2013."She needs to be able to answer the email question," said Democratic strategist Bud Jackson. "She hasn't quite hit that nail on the head yet. She should do better this time. And she should expect the unexpected."But Trump's troubles have loomed the largest, weighing down the New York businessman's extraordinary political run at the worst possible time.This has prompted him to lash out at what he feels is a political and media system rigged against him, an apparent bid to discredit the process before the election takes place. Obama said on Tuesday that Trump needs to "stop whining" and make his case to the voters.Republicans who have watched Trump shoot himself in the foot time and again said the Las Vegas debate was a final opportunity to appear presidential. "Trump needs to make a real closing argument and stop the personal attacks and come across like a commander-in-chief," said Republican strategist Scott Reed.Trump himself called the debate an important opportunity to talk to voters. The event, moderated by Fox New anchor Chris Wallace, is to include a discussion of six topics: debt and entitlements, immigration, the economy, the Supreme Court, foreign hot spots and fitness to be president."I see it as another important cog and really another important evening in the whole very complicated puzzle," Trump told conservative talk radio host Mike Gallagher.Clinton, who is now competitive in traditionally Republican states like Arizona, is considering a stop in Arizona in the closing three weeks of the campaign.Clinton senior adviser Jennifer Palmieri told reporters that the former U.S. secretary of state hopes to focus at the debate on what she would tackle if elected."If (Trump) chooses to continue to embrace his strategy of a scorched-earth campaign and bringing that to the debate stage, she'll be prepared to handle that as she has the last two times," she said.