With tensions high between the United States and Tehran, Iran's attempts to reach out to China have increasingly been put on public display.

Iranian Foreign Minister Mohammad Javad Zarif has made several trips to China in the past year.

That includes one highly publicized visit Zarif made to Beijing in late December and early January when the commander of Iran's Islamic Revolutionary Guards Corp was assassinated by a U.S. drone strike in Baghdad.

More recently, Zarif has tweeted messages in Chinese to mark the Chinese New Year, to praise Beijing's efforts to control a deadly outbreak of the coronavirus, and to express solidarity and support with the Chinese people.

"Iran stands with China," Zarif wrote in Chinese on February 4 in a tweet that also quoted a verse by 13th-century Persian poet Saadi. "The sons of Adam are limbs of each other, having been created of one essence," Zarif wrote in a Chinese translation of the Persian poet's work. "When the calamity of time affects one limb, the other limbs cannot remain at rest."

In another tweet, Zarif said he'd expressed "gratitude and appreciation" to Chinese Foreign Minister Wang Yi for what Zarif described as "successful measures" to fight the coronavirus.

Zarif referred to the Chinese foreign minister as his "good friend." He also criticized the United States for, in his words, "taking advantage" of the situation.

That remark appeared to refer to controversial comments made by U.S. Secretary of Commerce Wilbur Ross, who'd suggested that the coronavirus outbreak in China could be positive for the U.S. economy.

"Regardless of adversity, Iran has always stood by the Chinese people," Zarif tweeted on January 23.

In a recent interview with China's Phoenix Television that was posted online and shared widely, Zarif spoke a few words in Chinese to describe what he said was solidarity between Tehran and Beijing.

In another online video, Iranian Foreign Ministry spokesman Abbas Musavi spoke Chinese to express support for China during the difficult times the country is facing due to the coronavirus.

Iran also has donated some 3 million surgical masks to China to help combat the spread of the virus.

'Look To The East' Policy

Analysts say Tehran's public diplomacy efforts appear to be an attempt to strengthen the perception that Iran has a "solid international partnership" with China at a time Tehran faces international isolation and pressure.

"My impression is that part of this rhetoric is aimed to show Iran's goodwill towards Chinese authorities. But mainly, it is public-relations activity toward the entire international community," Jacopo Scita, an Al-Sabah doctoral fellow at Durham University, told RFE/RL. "Iran has a great need to show it is not isolated, and, again, these gestures are usually associated with strong international partnerships."

Iran has faced crippling U.S. economic sanctions since 2018, when Washington withdrew from Tehran's 2015 nuclear pact with world powers. Those sanctions include an oil embargo that has denied Tehran its main source of revenue and resulted in a shrinking economy.

Meanwhile, Iran has increasingly promoted its so-called "Look to the East" policy -- to China, as well as Russia -- for trade, support, and international partnerships. But analysts say China has not yet given Tehran the support it seeks.

"Iran hopes to count China, along with Russia, as a partner in the face of growing U.S. pressures to isolate it -- both in helping it bypass sanctions, and in being a political partner in fora like the United Nations," said Dina Esfandiary, a fellow at the Century Foundation think tank in New York.

Esfandiary said that "China has not been as forthcoming as Iran hoped, likely because of its own difficulties with the U.S."

Scita notes that despite China's position as the biggest buyer of Iranian oil, Beijing is unlikely to jeopardize its relationship with the United States in order to build better ties with Iran.

"However, so far Beijing has been Tehran's lifeline against U.S. sanctions," Scita said. "China has been the only major customer that kept buying Iranian oil after the expirations of waivers, while the level of trade between the two countries has decreased but remains tangible."

In fact, Washington has announced sanctions against several Chinese firms in recent months for defying the U.S. sanctions against Iran.

Analyst Esfandiary says Iran and China have been partners "through thick and thin, but the strength of the relationship oscillates depending on each country's relationship with the U.S. and the importance of the country at any given time to the other."

Big Plans, Shrinking Trade

In 2016, Chinese President Xi Jinping became one of the first world leaders to visit Tehran following the completion of the nuclear accord -- a pact that resulted in the lifting of sanctions against Iran in exchange for significant restrictions on its nuclear program aimed at preventing Tehran from developing nuclear weapons.

During the visit, Iranian President Hassan Rohani vowed a "new chapter" in relations between Tehran and Beijing, while promising to increase economic ties worth up to $600 billion within the next 10 years and build a stronger partnership as part of a 25-year plan.

The two countries then signed more than a dozen agreements, covering areas such as the economy, security, and nuclear cooperation. Esfandiary said that "it remains to be seen how much of this actually materializes under U.S. pressure."

Trade between Iran and China has also been significantly impacted by U.S. sanctions.

China relies on the Middle East for its energy supplies. It has condemned the U.S. sanctions and expressed its commitment to the 2015 nuclear deal.

But in a report released in January, China's General Administration of Customs said trade with Iran had dropped during 2019 by about one-third.

Iranian crude-oil exports to China averaged around 200,000 barrels per day (bpd) during the second half of 2019 compared to 400,000 bpd during the first half of the year, according to estimates by energy-sector monitor S&P Global Platts.

In 2018, Iran exported about 650,000 bpd to China, according to S&P Global Platts and shipping sources.

Scita says the economic gridlock Tehran is currently facing makes China "an indispensable partner." But he says that ties between the two countries will depend on Iran's international situation.

"If the path opened by the [nuclear deal] is relaunched, it is very much possible that Sino-Iranian relations will expand and find a new normal beyond the sanctions economy," Scita concluded.