Diplomacy and international relations are likely to play a role in the administration's determinations with China especially so long as there is some form of reductions to go along with the significant price squeezing by the Chinese.
"I think the administration is really trying to thread this needle delicately," said Mark Dubowitz, executive director of the Foundation for Defense of Democracies, who has followed the sanctions program closely. "Between on one hand really forcing Iranian oil off the market and forcing significant discounts on the oil that's being sold, but on the other hand not doing it too aggressively, because in doing so, it would face the possibility of returning to high oil prices we saw a month or two ago."
Both China and India have said they do not support either the EU or U.S. sanctions, and have not asked for a waiver.
For its part, Turkey, which along with South Africa, had recently ramped up its imports of Iranian oil in advance of the looming sanctions, is aware of the coming deadline.
TUPRAS, a private enterprise and Turkey's sole importer of Iranian crude, recently announced it would cut Iranian imports by 20% from the previous year's quantities. Presently, the crude imports from Iran account for 30% of Turkey's total imports, or just over 200,000 barrels a day, a Turkish official told CNN.
The company intends to replace that lost volume with Iran with additional purchases from Libya, the official said.
And because U.S. sanctions target any transactions of Iranian oil processed through Iran's central bank, Iran is facing a hard currency squeeze as more international banks refuse to repatriate any profits of oil sales back to Iran in their national currency, the rial. Iran is essentially being forced to barter and take profits in the form of the currency of the country purchasing the oil.
"Iran can't do anything with (Indian) rupees or (Chinese) yuan except buy Chinese and Indian goods and services that it really doesn't need," Dubowitz said. Without the ability to convert their sales into Iranian currency, and repatriate their profits, "all the oil they sell is going to be useless to them," he said.
Complicating matters even greater for those countries that are permitted to continue their purchases of Iranian oil at reduced rates is the increased difficulty in acquiring maritime insurance because of the sanctions.
With nearly 95% of all maritime insurance being underwritten in Europe, many of those insurers are denying coverage for anything that involves Iranian transactions.
In the absence of insurance, governments themselves would have to step in and guarantee liability on the event of a spill or some other catastrophe. Many Iran watchers expect the insurance sanctions to become particularly troublesome to Iran.
Whether the increasing pressure on Iran has brought about a willingness on its part to consider significant concessions on its nuclear program remains to be seen.
The so-called P5+1 group of the United States, Russia, China, France, Great Britain and Germany will discuss the issue with Iran in the Iraqi capital Wednesday. Most who follow the situation closely are skeptical about any significant announcements by Iran about its nuclear program in the near-term.
But regardless of whatever progress is made, some analysts say the United States should not be hasty in its response.
"I think the temptation which needs to be resisted is not to offer too much sanctions relief too fast," Dubowitz said. "Because this whole system which is being held together by the fear of U.S. penalties is going to quickly unravel, and I think the administration will lose all of the leverage that it so diligently assemble over the past few years."