MIAMI - A Miami judge on Wednesday agreed to delay pop star Justin Bieber's trial until July 7 on charges stemming from the Canadian singer's January arrest when he was caught allegedly drag racing on Miami Beach.

The trial was set to begin May 5, but lawyers for Bieber argued that more time may be needed to hear potential pre-trial motions.

"If the case goes ahead there are some motions that would require evidence," said Bieber's defense lawyer Roy Black. "There are some serious matters regarding the test," he added, referring to evidence that Bieber was driving under the influence of drugs and alcohol.

Bieber, 20, was charged with driving under the influence, resisting arrest and using an expired license after police stopped and arrested him while he was driving a rented yellow Lamborghini the morning of January 23. He has pleaded not guilty to the charges and, if convicted, could face six months in jail.

Police said two SUVs had blocked off the road so the singer could race a friend. Bieber cursed at police officers and later told police he had consumed alcohol, pot and prescription drugs, according to the arrest report.

A drug test found marijuana and prescription anxiety medication in his system at the time of the arrest, according to a spokesman for the Miami Dade county state attorney's office.

Bieber also faces charges and lawsuits in California and Toronto stemming from alleged behavior that has driven nonstop headlines. Shortly before his Miami arrest, detectives in California raided Bieber's home after he was accused of pelting a neighbor's house with eggs. In February, Bieber was charged with assaulting a limousine driver in Toronto in December.

A photographer is suing Bieber and one of his bodyguards in Miami court for allegedly assaulting him while he was taking photos of the Canadian-born singer leaving a recording studio.

Meanwhile, the White House last week said it would not respond to an online petition with more 270,000 signatures seeking to revoke Bieber's U.S. visa and deport him to Canada.

"We'll leave it to others to comment to Mr. Bieber's case," said the whitehouse.gov statement.