Countries are continuing to push back on the US decision to try to stop all Iranian oil exports. On Monday, Washington said it would end waivers that allowed nations to purchase Iranian oil without penalties for violating US sanctions. CGTN's Nathan King reports.  

The European Union became the latest international voice to criticize the U.S. action. Expressing regret, an EU spokesperson said Washington's move to cut Iran's oil exports "risks further undermining" the Iran nuclear deal.

That may be the point. Washington unilaterally withdrew from the Iran nuclear deal last November, reimposed sanctions and tried to get the EU and China to do the same. That did not happen. In fact, the EU has set up special financial structure to continue working with Iran outside of the U.S.-dominated financial system. China, too, has continued to buy large quantities of Iranian oil, but many smaller nations have been pressured into slashing Iranian oil imports-hitting Tehran hard.

One big Iranian oil buyer, Turkey, says U.S. sanctions are an international headache.

MEVLUT CAVUSOGLU TURKISH FOREIGN MINISTER "America's sanctions on Iran is not an issue that only concerns Turkey. I say it again. We are against all kinds of sanctions."

Meanwhile, as oil prices hit a high for the year, China is warning of rising regional tensions.

GENG SHUANG, SPOKESPERSON CHINESE FOREIGN MINISTRY "The relevant move of the U.S. will intensify the turmoil in the Middle East and the turmoil in the international energy market. We urge the U.S. to take a responsible attitude and play a constructive role, rather than doing the opposite."

Fears are that if countries find it too difficult to do business with Iran, Tehran might be tempted to also withdraw from the nuclear agreement or stop complying with it - unravelling the deal permanently.

NATHAN KING WASHINGTON "So far, Tehran is not doing that - dismissing the U.S. move as irrelevant and illegal. Tehran says however it will defend its sovereignty - some voices in the country have suggested closing the straits of Hormuz - the Iranian controlled waterway at the mouth of the oil-rich Persian Gulf. Such a move could lead to a military standoff with the US, or worse. Nathan King, CGTN, Washington."