The options include significantly expanding military action, the sources said.
President Donald Trump announced "major combat operations" against Iran on Feb. 28, with massive joint U.S.-Israeli strikes targeting military, government and infrastructure sites.
Delegations from the U.S. and Iran entered negotiations in June aimed at a war-ending deal based on a memorandum of understanding signed by both countries.
The U.S. and Iran have nonetheless continued to exchange strikes, with the strategic Strait of Hormuz the primary flashpoint.
U.S. military forces disabled a ship on Friday that was attempting to break the blockade, according to a U.S. official.
This is now the fifth ship that has been disabled by U.S. military forces since the blockade against ships leaving or going to Iranian ships was reimposed on July 14.
The U.S. struck a security building near the Iraq-Iran border crossing at Shalamche that was determined to be a "legitimate military target," according to an official.
The U.S. official who said that an initial look video showing explosions near the Iraq-Iran border said it was not from a U.S. airstrike, now says there was a U.S. airstrike near the border crossing.
The building targeted was located on the Iranian side of the border, about 8 meters from the border with Iraq, according to the official
-ABC News' Luis Martinez
An Omani diplomatic delegation visited Tehran for talks on the Strait of Hormuz, Iran's official Islamic Republic News Agency reported Friday.
The delegation will discuss mechanisms for governing the Strait of Hormuz, IRNA said.
Iranian Foreign Minister Abbas Araghchi told reporters that, "Iran has shown that it will not succumb to U.S. bullying and will not respond to the language of force, pressure, or threats in any way."
"We are neither afraid of threats nor will we succumb to pressure and will not tolerate the language of threats. We have a principled policy and we will continue to do so. Protecting the Iranian people and protecting Iran's interests in the Strait of Hormuz are among our principles and we will follow them," Araghchi said at the Council of Ministers of Foreign Affairs of the Shanghai Cooperation Organisation in Kyrgyzstan.
On negotiations, Araghchi said there was no issue with mediators, but that the problem lies with the United States' approach.
