Riyadh (AFP) - Saudi Arabia's foreign minister has been lobbying US legislators to change a law allowing victims of the September 11, 2001, attacks to sue the kingdom, he said on Sunday.

Adel al-Jubeir told reporters he has just returned from an extended stay in the United States, which was partly "to try to persuade them that there needs to be an amendment of the law", the Justice Against Sponsors of Terrorism Act (JASTA).

The US Congress voted overwhelmingly in September to override President Barack Obama's veto of the JASTA.

Fifteen of the 19 Al-Qaeda hijackers who carried out the 9/11 attacks were Saudi. But Riyadh denies any ties to the plotters who killed nearly 3,000 people.

JASTA allows attack survivors and relatives of terrorism victims to pursue cases against foreign governments in US federal court, and to demand compensation if those governments are proven to bear some responsibility for attacks on US soil.

"We believe the law, that curtails sovereign immunities, represents a grave danger to the international system," Jubeir said at a joint press conference with visiting US Secretary of State John Kerry.

In opposing the law, Obama said it would harm US interests by opening up the United States to private lawsuits over its military missions abroad.

Saudi Arabia's Gulf allies have also expressed concern about erosion of sovereign immunity, a principle sacrosanct in international relations.

But the potential implications go far beyond the Gulf.

Some British, French and Dutch lawmakers have threatened retaliatory legislation to allow their courts to pursue US officials, threatening a global legal domino effect.

"The United States is, by eroding this principle, opening the door for other countries to take similar steps and then before you know it international order becomes governed by the law of the jungle," Jubeir said.

He added that the US itself would suffer most from the erosion of sovereign immunity.

"The question now becomes how do you go about amending the law", he said.

Kerry, whose visit was focused on the war in Yemen, at the press conference reiterated his government's concern over JASTA.