New York, United States - Saudi Arabia has again defended its government against allegations of providing support to the perpetrators of the September 11, 2001, attacks in New York, as the kingdom's lawyers faced family members of victims in a Manhattan federal courtroom.

Thursday's hearing marked the third time a group of families of 9/11 victims and survivors have tried to sue the Saudi government for damages relating to the attack that killed nearly 3,000 people.

Fifteen of the 19 attackers were Saudi citizens.

It was the first hearing since Congress passed legislation removing aspects of sovereign immunity that had prevented previous cases against the Saudi government from being heard.

Victims' relatives, survivors and insurance companies have claimed that members of the Saudi government supported the al-Qaeda-affiliated men who hijacked and crashed planes into New York's World Trade Center, the Pentagon outside Washington, and a Pennsylvania field.

They also accuse Saudi Arabia of funding charities that supported al-Qaeda.

Terry Strada, national chair of 9/11 Families and Survivors United for Justice Against Terrorism, fought for the legislation to limit sovereign immunity.

She said her group would keep pushing to expose what she sees as clear financial ties between the attack and the royal family.

"I'll never be tired of doing this," Strada told Al Jazeera. "We will fight until the end."

She said her life had not been the same since she lost her husband, Tom, the father of her three children.

"I don't have anything else. I'm going to take this as far as I can."

In 2015, the suspicion that the Saudi attackers had help from their government was investigated and dismissed for lack of evidence by the 9/11 Commission.

But lawyers for the plaintiffs say the commission's report was inconclusive, and new evidence has since come to light, including previously classified documents and supporting testimony from two former FBI agents and former Senator Bob Graham of Florida, who served on the 9/11 Commission.

'Hearsay and speculation'

Lawyers for Saudi Arabia say the accusations are "baseless" and are again trying to get the case dismissed, arguing in court documents that the new evidence is "hearsay and speculation, insufficient to support the findings required for jurisdiction over Saudi Arabia".

The families believe the evidence shows that US-based Saudi government agents helped the hijackers and that the government knowingly funded charities that supported "anti-Western, jihadist ideology".

Lawyer Sean Carter, who represents victims and their family members, told the judge that the charities were "the principal source of funding for al-Qaeda leading up to the 9/11 attacks".

He argued the judge should allow the case to move forward to the next phase, when the plaintiffs would be able to summon prominent members of the Saudi royal family and religious leadership to testify and provide documents.

Saudi officials are trying to stop that from happening and accuse the plaintiffs of equating Islam with "terrorism".

"To equate missionary work, building mosques, providing Qurans, with terrorism is not proper in this court," lawyer Michael Kellogg argued in court.

The judge could take up to four months to decide whether or not to let the trial proceed.

If the trial is allowed to continue, it is likely to strain diplomatic and economic relations between the US and Saudi Arabia.