“Certain foreign companies which have left Iran in recent years and months – submitting to the banditry of the United States – should know that returning to the Iranian market will be much more difficult than entering it,” Foreign Ministry spokesman Abbas Mousavi tweeted on Friday, Press TV reported.

“The principles of trade maintain that conserving one’s foothold in a market is harder than entering one,” he said, adding that Iranians will also “not forget friends who stand at their side at times of hardship.”

The spokesperson attached a photo of workers removing a banner of South Korea’s tech giant Samsung in Iran.

The tweet came as Samsung and its fellow South Korean company LG Electronics – for which Iran has been a key market in the Middle East – reportedly pulled down their last advertisement banners in Iran on Friday.

The two companies had cut their trade relations with Tehran in the past months, submitting to US sanctions imposed on Iran after Washington withdrew from the 2015 Iran nuclear deal in May 2018.

Both companies enjoyed major home appliances sales in Iran, being popular brands for items such as TV sets, air conditioners, telecommunications equipment and washing machines.

Samsung’s sales also notably covered about half of Iran’s lucrative android phone market, with almost 18 million Iranians having Samsung devices as of February 2018, according to a report published by Iran’s largest app market Café Bazaar.

In November, head of Iran’s home appliances union Morteza Miri said that Samsung and LG’s affiliated companies in Iran – Sam and Gplus respectively – will continue production despite the departure of the South Korean companies.

He said that the two affiliated Iranian companies will continue production with “their own equipment, personnel and production lines” and that they have negotiated to import needed material from Chinese companies.

The departure of Samsung and LG from Iran came as both companies – unlike certain other South Korean businesses in Iran – had stayed their ground in Iran when the US-led sanctions were imposed in 2011.

Following the removal of sanctions resulting from the Iran nuclear deal in 2015, Seoul expressed remorse for previously abandoning trade with Iran, and rushed to ink new trade deals with the country.

According to a statement by the Ministry of Trade, Industry, and Energy in Seoul, Iran was once the sixth-largest market in terms of orders won by South Korean builders before the 2011 sanctions.

Seoul has been currently forced to comply with new Trump administration sanctions on Iran despite openly acknowledging that Washington’s unilateral measures hurt South Korean companies.

Last year, Washington effectively banned the country from importing Iranian oil.

Before the sanctions, South Korea was the biggest client of Iranian condensate with 300,000 barrels per day (bpd) on top of 100,000 bpd of crude oil.