Iran has said it will retaliate following the US Supreme Court's decision to partly reinstate a travel ban on six Muslim-majority countries.

Earlier this year, lower courts in the US blocked a proposition by President Donald Trump to impose a 90-day travel restriction on people form Iran, Libya, Somalia, Sudan, Syria and Yemen, along with a 120-day entry ban on refugees.

The Trump administration said the ban was necessary on grounds of national security and to allow the implementation of new immigration vetting procedures.

However, the supreme court said on Monday (26 June) the ban could be enforced in case people who applied from the targeted countries lack "a credible claim of a bona fide [authentic] relationship with a person or entity in the United States".

Iran's Foreign Ministry Spokesman Bahram Qassemi slammed the court's ruling as an indication of the "US government's discriminatory behavior towards Muslims and also shows the unfair look the country gives to them" ,the official Islamic Republic News Agency (IRNA) reported.

"The Islamic Republic of Iran, after carefully examining the recent decision of the Supreme Court of America, will take proportional and reciprocal action," Qassemi said, but did not elaborate further.

At the moment, US citizens planning to travel to Iran need to apply for a visa beforehand.

The spokesperson added that the US was targeting the "wrong countries" with its travel ban, Reuters said.

"It's regrettable that the American government, because of their economic and commercial short-sightedness, have closed their eyes to the main perpetrators of terrorism in America," he said, in what seems as a reference to Saudi Arabia, a close ally of US and Iran's regional adversary.

Tehran accuses Saudi Arabia of sponsoring terrorist groups, an accusation that Riyadh denies.

Relations between Iran and Saudi Arabia have further strained following the decision of some Arab countries to isolate Qatar diplomatically and economically, sparking what has been deemed as one of the worst Gulf crises in recent years. Iran – along with Turkey – backs Qatar.