Vice President Kamala Harris and other world leaders are gathering in Paris on Friday to make a diplomatic push in support of coming elections in Libya that could make or break the peace process in a country that has been torn apart by war and political crisis for a decade.

Ms. Harris, German Chancellor Angela Merkel, French President Emmanuel Macron and other European and Middle Eastern leaders are attending the gathering. France wants the election to be held as scheduled on Dec. 24 in hopes that it will provide a definitive...

Vice President Kamala Harris and other world leaders are gathering in Paris on Friday to make a diplomatic push in support of coming elections in Libya that could make or break the peace process in a country that has been torn apart by war and political crisis for a decade.

Ms. Harris, German Chancellor Angela Merkel, French President Emmanuel Macron and other European and Middle Eastern leaders are attending the gathering. France wants the election to be held as scheduled on Dec. 24 in hopes that it will provide a definitive solution to Libya’s political crises since the 2011 ouster and death of dictator Moammar Gadhafi.

The conference comes as Western officials fear that a dispute among rival Libyan factions over the election’s timing, legal basis and rules threatens to unravel a United Nations-brokered cease-fire that ended a 14-month war last year. Time is running out to organize polling, distribute ballots, register candidates and allow for campaigning.

Some Libyan officials and observers are calling for the vote to be delayed, arguing that a hastily organized election raises the risk of a disputed outcome that could plunge Libya back into conflict.

“If elections take place on the 24th and a controversial candidate wins, then that is the end of the democratic process and part of Libya will not accept the results,” said Otman Gajiji, the former head of Libya’s High National Elections Commission.

Postponing the election also holds risks. Politicians in eastern Libya, who are calling for holding the election on time, could use a postponement to break with the country’s interim unity government, thrusting the country back into a state of disunity and raising the chance of conflict, proponents of holding the vote in December say.

“Holding presidential and legislative elections is vital to stability and political reconciliation in Libya,” a French foreign ministry spokesperson said earlier in November, answering a question about postponing the election.

Biden administration officials say that while the decision is in Libyans’ hands, the U.S. wants to help Libya hold the election in keeping with the timeline set by the U.N.-brokered peace process. Not holding the election on time would also be destabilizing, a senior administration official told reporters traveling with Ms. Harris.

“Our view is without these elections you’re not going to have a functioning government in Libya next year,” the senior administration official said.

Aspiring strongmen are now looming large over Libya’s coming election. Among the possible candidates is Russian-backed warlord Khalifa Haftar, who attacked Tripoli in 2019 and is battling civil litigation in the U.S. over alleged war crimes committed by his forces. The International Criminal Court issued an arrest warrant for one of his lieutenants for alleged summary executions. Mr. Haftar and his lieutenant deny wrongdoing.

The deceased dictator’s son, Seif al-Islam Gadhafi, has also expressed interest in running in the election, alarming many Libyans but stirring the hopes of a small faction that remains loyal to the old regime. The younger Mr. Ghaddafi is also wanted by the ICC for alleged war crimes committed during the 2011 revolution. He has denied wrongdoing.

The prime minister of Libya’s interim unity government, Abdul Hamid Dbeibah,

is also expected to be running in the election, upsetting officials in eastern Libya, including Mr. Haftar’s allies who say the current premier shouldn’t be allowed to run.

The Paris conference is also designed to push for the removal of foreign fighters from Libya. Thousands of Syrians and other fighters have fought on both sides of the civil war, including mercenaries brought in by both Turkey and Russia.

Foreign powers have been deeply involved in the conflict, including Egypt, the United Arab Emirates, and France, which have all offered military support to Mr. Haftar, viewing him as a bulwark against extremists. Turkey also sent armed drones, air defenses and Syrian fighters to help Libya’s internationally recognized government fight back against Mr. Haftar.

Libyan observers are concerned that, if held on time, the December election would suffer from low turnout, security problems, fraud and a disputed outcome.

“The risk of having a really poorly prepared election, that doesn’t engage the public, that can’t produce security guarantees, where nobody looks likely to respect the outcome—the risk of doing that is far greater than a planned postponement,” said Tarek Megerisi, a senior policy fellow at the European Council on Foreign Relations, a think tank. “Better to fix the process.”

Write to Jared Malsin at jared.malsin@wsj.com