The lawyer for a Canadian man accused in a massive hack of Yahoo emails said Wednesday he will go ahead with an extradition hearing unless negotiations with American authorities pan out before then.

Karim Baratov's lawyer said that if an agreement with the U.S isn't reached by the Sept. 8 hearing, he plans to fight to keep his client in Canada.

Baratov was arrested in Hamilton in March under the Extradition Act after U.S. authorities indicted him and three others -- two of them allegedly officers of Russia's Federal Security Service -- for computer hacking, economic espionage and other crimes.

His lawyer, Amedeo DiCarlo, said last month that Baratov was considering bypassing his extradition hearing in an effort to speed up the legal process. But DiCarlo said Wednesday that talks are taking longer than expected and it may be faster to follow the usual steps.

"I can't get things done quick enough," DiCarlo said outside a Hamilton court after his client made a brief appearance before a judge.

"In any event, the priority is here -- Karim is in custody and his legal rights are here," he said.

"If something does come to light in the U.S. that totally changes my viewpoint, I'll let everyone know and then I could waive (the hearing) at that point."

DiCarlo has previously said Baratov is getting bored behind bars, and that he doesn't want his client to spend more time than necessary in custody if it looks like he could be exonerated or spared incarceration in the U.S.

He has stressed that waiving the extradition hearing does not mean admitting guilt.

An Ontario Superior Court judge ruled that Baratov, 22, was too much of a flight risk to be released on bail before his extradition hearing, a decision that was upheld on appeal.

Yahoo said last September that information from at least 500 million user accounts had been stolen in a cyberattack two years earlier.

Baratov is accused of hacking 80 Yahoo accounts and faces up to 20 years in prison in the U.S. if convicted.

Also indicted in the alleged conspiracy were Dmitry Aleksandrovich Dokuchaev, 33, Igor Anatolyevich Sushchin, 43, and Alexsey Alexseyevich (Magg) Belan, 29, all Russian nationals and residents. Dokuchaev and Sushchin were said to be Russian intelligence agents who allegedly masterminded and directed the hacking, U.S. officials have said.

Dokuchaev and Sushchin allegedly tasked Baratov with hacking accounts in exchange for commissions, according to U.S. authorities, who submitted a provisional arrest warrant to Canadian authorities March 7.

Belan, who had previously been indicted in 2012 and 2013, was named one of FBI's most wanted cyber-criminals in November 2013 but escaped to Russia before he could be extradited from Europe, the department said.