Donald Trump and Kamala Harris will lead dueling rallies Friday in Michigan, a crucial battleground state where Arab American voters angered by US support for Israel may hold the key to a deadlocked race.

The killing of Hamas chief Yahya Sinwar drew optimism from Vice President Harris for a Gaza ceasefire, but Israel quickly said his death is not the end of over a year of war.

Harris has found herself on eggshells as she upholds President Joe Biden's support for key ally Israel, while Muslim and Arab American voters have voiced outrage over the death toll in Gaza.

One of those voters in the extremely close race, 51-year-old Marwan Faraj, said he supported Biden but won't cast a ballot for Harris because of her backing for Israel.

"They have been supporting this ethnic cleansing and genocide since day one, with our tax dollars, and that's wrong," said Faraj, who emigrated from Lebanon, referring to Biden and Harris.

The vice president, who replaced Biden on short notice in the race just three months ago, is holding a series of campaign events in Michigan on Friday to try to convince voters to back her.

"This moment gives us an opportunity to finally end the war in Gaza," Harris said in reaction to Sinwar's death, "and it must end such that Israel is secure, the hostages are released, the suffering in Gaza ends."

Very close race

The Uncommitted movement, a pro-Palestinian group, stopped short of explicitly endorsing Harris earlier this month, but warned "it can get worse" under Trump. 

One of the group's co-founders, Lexi Zeidan, said voters should consider "the better antiwar approach" rather than "who is the better candidate."

However, Abandon Harris, another group of anti-war voters, has endorsed fringe Green Party candidate Jill Stein, potentially turning her into a spoiler that would help elect Trump in swing states decided by just a few thousand votes.

Harris's rival in the November 5 election, former president Trump, has yet to react to Sinwar's killing but has expressed support for the Israeli campaign in response to Hamas's October 7, 2023 attack. 

The Republican candidate will also be in Michigan on Friday, for a major campaign rally in auto industry capital Detroit. 

According to his campaign team, this will be an opportunity to detail how Michigan families have been hit by inflation under Biden and Harris's leadership. 

The economy, immigration and abortion are among the most hotly debated issues in a particularly tense and close election. 

The candidates are racing toward election day with the Democratic vice president narrowly leading her Republican rival nationally and in several crucial swing states, although most polls are within the margin of error.

Harris's momentum in the polls has plateaued in recent weeks, however, and both candidates have been on a blitz of new and traditional media as they try to win over the small number of undecided voters.