The historic opening of the Iraqi-Saudi border is an “investment gateway” that will strengthen economic relations after 30 years of sealed land borders between the two nations, diplomats said on Thursday. Access through the Saudi town of Arar, 70 kilometres from the Iraqi border, was closed after Iraqi dictator Saddam Hussein's invasion of Kuwait. Its reopening on Wednesday marked a major breakthrough in ties between Riyadh and Baghdad. "We are proud of our relations with our brotherly nation, Iraq cannot be separated from its Arab ties,” said Qahtan Taha Khalaf, Iraqi ambassador to Saudi Arabia. Mr Khalaf said the border is open only for trade but visitors will soon be able to cross as well. “We look forward to further partnership between the two countries,” he said. Riyadh and Baghdad have been at loggerheads since the Iraqi invasion of Kuwait in 1990, but the reconciliation of relations began after the US-led invasion of Iraq in 2003. “We are celebrating an accomplishment,” Saudi ambassador Abdulaziz Al Shammari said shortly after the ceremony. “We welcome all Iraqi products to be exported to Saudi Arabia, and through this border, there will be an exchange of visits between the two countries,” he said. Baghdad sees Arar as a potential alternative to its crossings with neighbouring Iran, through which Iraq brings in a large proportion of its imports. Before Arar's opening, a group that identified itself as Ashab Al Kahf published a statement announcing its "rejection of the Saudi project in Iraq". "The intelligence cadres of the Islamic Resistance are following all the details of the Saudi enemy's activities on the Iraqi border," it said. Prime Minister Mustafa Al Kadhimi fired back against those describing the rapprochement as Saudi colonialism. "This is a lie. It's shameful," Mr Al Kadhimi said on Tuesday night. Mr Al Kadhimi is closely connected with officials in Jeddah and shares personal relations with Saudi Crown Prince Mohammed bin Salman. A monumental moment in their relations was in 2016 when Saudi Arabia reopened its embassy in Baghdad, after 25 years. In October 2017, two months before Iraq declared victory over ISIS, the countries established the Iraqi-Saudi Joint Co-ordination Council, to help rebuild devastated areas retaken from the militants in Iraq. In March 2018, Riyadh pledged $1 billion to Baghdad for the construction of a sports city, as well as four consulates, including one in Baghdad and three others around the country.