The United States warned on Tuesday world countries against purchasing oil from Iran after November 4 or face renewed American economic sanctions. A senior State Department official warned foreign capitals "were not granting waivers" and described tightening the noose on Tehran as "one of our top national security priorities." "Were going to isolate streams of Iranian funding and looking to highlight the totality of Irans malign behavior across the region," the official, speaking on condition of anonymity, told reporters. Last month US President Donald Trump withdrew the United States from the Iran nuclear deal, re-imposing US sanctions that had been suspended in return for controls on Tehrans nuclear program. Now, Washington is stepping up pressure on other countries to follow suit, including European allies who begged him to stay in the accord and major Iranian customers like India, Japan and China. European powers in particular have been attempting to negotiate exemptions for their firms, but the official confirmed that Trump intends to stick to his 180-day deadline, expiring November 4. "I would be hesitant to say zero waivers ever," he said, but added that the official position is: "No, were not granting waivers." The senior US official admitted that this would be unpopular. "I dont think the Japanese answer was particularly different than other oil importing countries," the official said, adding that he plans to visit China and India soon to discuss the matter. "This is a challenge for them, this is not something that any country that imports oil from Iran ... wants to do voluntarily because, you know, were asking them to make a policy change. "China, India? Yes, certainly their companies will be subject to the same sanctions that everybody else is," he said. "We will certainly be requesting that their oil imports go to zero." The official said a US delegation was headed to the Middle East next week to urge Gulf producers to ensure global oil supplies as Iran is cut out of the market starting on November 4. Officials have yet to hold talks with China and India, among the largest importers of Irans oil, as well as Turkey and Iraq. European powers have vowed to keep the 2015 deal alive without the United States by trying to keep Irans oil and investment flowing, but have acknowledged that US sanctions would make it difficult to give Tehran guarantees. "For the vast majority of countries they are willing to adhere and support our approach to this because they also view" Irans behavior as a threat, the official added. The Iranian capital Tehran has been rocked with rallies in recent days by demonstrators protesting the deterioration of their countrys economy, caused in part by the US withdrawal from the nuclear deal.