In contrast to the hardening US position against Iran, the other parties to the Iranian nuclear deal are stepping up their communication in a bid to keep the Iran nuclear deal alive.

Iranian President Hassan Rouhani made what was described as a visit of "prime importance" to Europe from Monday to Wednesday to gain a more precise picture of cooperation between Iran and Europe ahead of the meeting for the top diplomats from the signatory countries, except of course the United States, convened by Federica Mogherini, the high representative of the European Union for foreign affairs and security policy.

The Vienna meeting will be the first between the other parties to the deal since the US withdrawal and such intensive diplomacy is essential if the deal is not to fall apart. And it is worth upholding the 2015 Joint Comprehensive Plan of Action, the formal name of the deal, as it marks a significant breakthrough in multinational efforts to prevent the proliferation of nuclear weapons. Despite US President Donald Trump claiming it was a "bad deal", it established a transparent and stringent process for inspecting Iran's nuclear activities that has proved effective and which has shown it has fully complied with the restrictions imposed on it.

When Trump announced he was withdrawing the US from the multilateral agreement, his administration set 90-day and 180-day wind down periods before it would fully revive its sanctions regime against Teheran. Considering that there is only one month left before the first deadline, it is hoped the other signatory countries will send a signal of solidarity during the Vienna meeting.

If the US reimposes sanctions on Teheran and makes good on its threat of long-arm punishment of those conducting normal business with the Middle East country, the US will not only further disrupt the workings of international trade but also undermine the norms governing nation-to-nation ties.

A signatory state to the Iran deal, China opposes the US' unilateralism. It rightly regards the Iran deal as an important achievement of multilateralism and remains a staunch supporter of it.

Much has changed in the world arena since the deal took effect three years ago. But the deal's role in preventing further chaos in the Middle East and upholding the international nuclear weapons nonproliferation regime should not be underestimated.

This is especially true when good momentum on resolving the nuclear issue on the Korean Peninsula has emerged of late. Retrogression in the Iranian nuclear issue will not bode well for attempts to finally secure a breakthrough in the Democratic People's Republic of Korea nuclear issue.