MOGADISHU, March 10 (Xinhua) -- Somali President Mohamed Abdullahi Farmajo on Saturday urged foreign countries and investors to follow legal procedures for investment in his country, in an apparent response to a dispute over a port deal in the breakaway region of Somaliland.

"I am warning companies and countries not to cross the line and put to question the sovereignty of Somalia," he told the opening session of parliament.

"Somalia is open for business and international partnerships, but those who want to invest here must get the approval of the respective state institutions," he said.

Farmajo said any trade agreements must be made within the dictates of the law, warning against infringing on the country's sovereignty and unity.

His remarks come amid what is escalating into a diplomatic tiff between Somalia and the United Arab Emirates (UAE) over the March 1 deal.

In the agreement, UAE-controlled DP World and Somaliland announced they would cede part ownership of the port management to allow landlocked Ethiopia to get a 19 percent holding.

Somaliland parliament approved the Berbera Port concession in August 2016, granting DP World 65 percent stake in the 30-year concession.

Mogadishu has rejected the deal and declared it null and void.

Farmajo did not mention the issue of Berbera but his comments, coming one day after the Arab League called for respect of territorial integrity, added voice to his government's concerns over the concession.

Somalia submitted a petition to the Arab League on Friday seeking intervention over the port issue.

Somaliland has maintained it will proceed with the concession despite objections from Mogadishu.