"Our goal with respect to the energy sanctions, our goal is to increase pressure on the Iranian regime by reducing to zero its revenue from crude oil sales," Brian Hook told reporters.
The US administration is also working to minimize disruptions to the global oil market due to the counter-Iran sanctions, but it is confident there is enough spare oil production capacity in the market, Hook added.
"We are not looking to grant licenses or waivers because doing so would substantially reduce pressure on Iran, and this is a campaign of imposing pressure," Hook said. "We are prepared to work with countries that are reducing their imports on case by case basis, but as with our other sanctions we are not looking to grant waivers or licenses."
Oil prices raised this week after Washington stated it would offer no extensions or waivers to Iran's oil buyers when sanctions return in November.
In addition, the US president decided to reinstate sanctions on Iran, previously lifted under the agreement in exchange for Tehran maintaining a peaceful nuclear program. The unilateral move taken by the United States has been opposed by other signatories of the nuclear agreement.
Iranian President Hassan Rouhani earlier met with the officials of the legislative and the judicial branches of government to discuss measures aimed at adjusting for possible sanctions in order to "prevent their negative impact."
The first part of the sanctions will take effect on August 6, targeting Iran’s automotive sector, trade in gold, and other vital metals, Hook said. The remaining sanctions will snap back on November 4 against Iran’s energy sector, petroleum-based transactions, and transactions with Iran’s Central Bank, he added.
The Trump administration is not seeking regime change in Iran, only a change of Tehran’s behavior, Hook said. He added that Iran has been using money received through the JCPOA to fund destabilizing activities in the Middle East, including Syria.