Iran's foreign minister is pressing ahead with intense diplomatic efforts to salvage Tehran's nuclear deal with world powers at the centre of a crisis unfolding between Iran and the US.

The Trump administration pulled America out of the 2015 deal last year and imposed escalating sanctions ─ the latest levied as recently as last week ─ that have crippled Iran's economy.

Other signatories to the deal the European Union, France, Britain, China and Russia have been trying to salvage it.

Read: Iran says exercising restraint despite 'unacceptable' escalation of US sanctions

Mohammad Javad Zarif chastised the international community, saying that so far, it has "mainly made statements, instead of saving the deal," according to the official IRNA news agency. He spoke in China on Friday after visiting Japan.

Iran has warned it will resume enriching uranium at higher levels if a new nuclear deal isn't reached by July 7.

Read more: What is the Iran atomic deal and why is it being targeted

The US in February this year also began withdrawing from the 1987 Intermediate-Range Nuclear Forces treaty signed with Russia, with analysts worrying its demise could fuel a new arms race.

Rising tensions in ME

Concerns about a possible conflict in the Middle East flared after the US dispatched warships and bombers to the region to counter an unspecified threat allegedly from Iran.

The US State Department has ordered all nonessential government staff to leave its embassy and consulate in Iraq. Last week, the US Secretary of State Mike Pompeo made an unexpected trip to Iraq, where he sought assurance of safety for US interests from Iran.

Germany and the Netherlands both suspended their military assistance programmes in the country in the latest sign of tensions.

Iraq is home to suspected pro-Iran militias, while also hosting more than 5,000 US troops. The US military's Central Command said its troops were on high alert, without elaborating.

Saudi Arabia has accused Tehran of being behind a drone strike that shut down a key oil pipeline in the kingdom, and a newspaper close to the palace called for Washington to launch strikes on Iran, raising the spectre of escalating tensions as the US boosts its military presence in the Persian Gulf.

There also have been allegations that four oil tankers were sabotaged on Sunday off the coast of the United Arab Emirates (UAE), and Houthi rebels in Yemen claimed responsibility for Tuesday's attack on the Saudi pipeline.

Iran has been accused by the US and the United Nations of supplying ballistic missile technology and arms to the Houthi rebels, which Tehran denies.

A senior British officer part of the US-backed coalition fighting the militant Islamic State (IS) group, Maj Gen Chris Ghika, said earlier this week that there had been no increased threat from Iranian-backed forces in Iraq and Syria. His comments exposed international scepticism over the US military buildup.

Trump on Thursday appeared to take a softer tone on the issue, a day after tweeting that he expected Iran to look for talks. Asked if the US might be on a path to war with the Iranians, the president answered, “I hope not”. His words, however, were at odds with recent moves by Washington.

Where KSA stands

Saudi Prince Khalid bin Salman, who is King Salman's son and the country's deputy defence minister, tweeted that the drone attack on two Saudi Aramco pumping stations running along the East-West pipeline were “ordered by the regime in Tehran, and carried out by the Houthis”.

A state-aligned Saudi newspaper went further, running an editorial calling for US strikes on Iran in retaliation.

The front-page editorial in the ArabNews, published in English, said it's “clear that (the US) sanctions are not sending the right message” and that “they must be hit hard,” without elaborating on specific targets.

It said the Trump administration had already set a precedent with airstrikes in Syria, when the government there was suspected of using chemical weapons.

Ali Shihabi, who runs the Saudi-leaning Arabia Foundation in Washington, said there's a sense that if the Iranians can get away with targeting Saudi oil infrastructure, then “the whole security infrastructure in the Gulf will be called into question and security premiums on oil will rise.”

He said it would seem that Riyadh would like to coordinate with Washington how it responds to Iran, but “eventually what may happen is that just Saudi Arabia and the UAE may have to do something.”

Saudi Crown Prince Mohammed bin Salman, who is also defence minister and controls major levers of power in the kingdom, has not commented publicly on this week's incidents.