"There is no embargo", he said.
The coalition closed all air, land and sea access to Yemen last week following the interception of a missile fired toward the Saudi capital, saying it had to stem the flow of arms to the Houthis from Iran. "There are many sources of supply to Yemen, even during the past week or so".
The announcement from the Saudi mission at the United Nations came after the coalition fighting Yemen's rebels, known as Houthis, faced widespread worldwide criticism over the closure, with the U.N. and over 20 aid groups saying it could bring millions of already suffering people closer to "starvation and death".
Al-Mouallimi also accused the Houthis of diverting humanitarian aid "to fulfill their own requirements" and "to trade in the black market and achieve exorbitant profits at the expense of the Yemeni people". The Saudi closure had drawn global condemnation and fears of a worsening humanitarian disaster in Yemen.
"The coalition, in consultation and full agreement with the legitimate government, will begin steps related to re-opening of airports and ports in Yemen to allow the transport of humanitarian and commercial cargo", the statement said.
Protesters gathered outside the United Nations office in central Sanaa amid chants decrying the Saudi-led blockade and airstrikes in the war-torn country.
The mission's announcement came in a statement early on Monday.
He did not give any reasons for the reopening of the port, which is located in the south of the country - though the coalition greatly controls Aden.
"The port at Aden does not have the capacity for commercial and humanitarian cargo, and unless the Red Sea ports in Hodeida and Saleef are opened immediately, the United Nations will not be able to feed 7 million people every month", said United Nations spokesman Stephane Dujarric.
The Saudi-led coalition has been targeting the Houthis since they seized parts of Yemen in 2015, including the capital Sanaa, forcing President Abd-Rabbu Mansour Hadi to flee and seek help from neighboring Saudi Arabia. Saudi officials say the missile was supplied by Iran, and enforced the blockade as retaliation. The Houthis have denied that.