Without detailing how far Riyadh might go to retaliate, Foreign Minister Prince Saud al-Faisal told reporters in Austria that his country "will not bow" to such a plot.
"We hold them accountable for any action they take against us," he said, pledging a "measured response." When asked what options the Saudis were considering, he said, "We have to wait and see."
The comments come as U.S. officials say they will employ sanctions and diplomatic pressure on Iran to further isolate the regime. President Obama said Thursday that the U.S. takes no options off the table, but he expressed confidence that the international community would ensure Iran "pays the price" for its behavior.
Sources have told Fox News that the announcement of charges Tuesday by the Justice Department was not a prelude to a U.S. military response.
Sen. Dianne Feinstein, D-Calif., also said Wednesday that she doesn't think military action is appropriate.
But Saudi Arabian officials, who oversee one of the most powerful air forces in the Middle East, have not said what options of theirs are on or off the table.
State Department spokeswoman Victor Nuland acknowledged Wednesday that the U.S. is concerned about escalating tensions between the two countries.
"Obviously, this is a matter of concern. The relations have not been good for a while," she said. "This is not the first effort by Iranian operatives to threaten official Saudis. So obviously we are concerned there."
She said nobody "is seeking a wider conflict here."
Information released by the Justice Department shows that Saudi institutions were the primary aim of the alleged perpetrators. The suspect in custody not only wanted to assassinate the Saudi ambassador but inquired about attacking a Saudi embassy.
U.S. officials say members of the special operations Quds Force were involved in the planning, though Iran has denied the United States' claims.
The Saudi embassy in Washington, D.C., called the plot a "despicable violation of international norms, standards and conventions."
In a statement Wednesday, the embassy said the country would coordinate with U.S. officials
"regarding this despicable plot and those behind it."
"At the same time, the Kingdom is considering the critical procedures and steps that must be taken in this regard to stop these criminal acts and to firmly address any attempts to destabilize the Kingdom, threaten its security and spread sedition among its people," the statement said.
Obama said Thursday that countries in the Middle East will "question their ability to work with Iran" in the wake of the plot.
The Associated Press contributed to this report.