Dubbed the Suez Canal Axis, the new 72-kilometre (45-mile) section built by the Egyptian army is aimed at speeding up traffic along the existing waterway by reducing the waiting period, as well as boosting revenues.
It runs part of the way along the existing canal connecting the Red Sea to the Mediterranean.
"We declare that the new Suez Canal is safe for all kinds of vessels," Suez Canal Authority chief Mohab Mameesh told a news conference in the canal city of Ismailiya.
"We call on all the international maritime carriers to use the current and the new Suez canal. Your navigation is safe."
A ceremony will be held on August 6 to inaugurate the project. The authorities held the first trial run of the new waterway on Saturday.
Preparations for the inaugural ceremony were in full swing in Ismailiya amid a widespread campaign to clean the city, an AFP correspondent reported.
Three large tents were being put up for invitees, and hundreds of Egyptian flags were seen in the streets as security forces deployed around the entrances to the canal city.
The new waterway involved 37 kilometres of dry digging and 35 kilometres of expansion and deepening of the existing canal.
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"By reducing the navigation time in the Suez Canal, your food, your medicine and your fuel will arrive faster. It will be Egypt's gift to the world," Mameesh said.
Officials say the new waterway will help cut the waiting period from 18 hours to 11.
President Abdel Fattah al-Sisi launched the project in August 2014 and set an ambitious target of digging the expanded canal within a year.
The canal is part of a plan to develop the surrounding area into an industrial and commercial hub that would include the construction of ports and provide shipping services.
The new route is considered a "national project" that aims to kick-start an economy battered by years of political turmoil since the ouster of president Hosni Mubarak in 2011.
Authorities raised $9 billion (7.9 billion euros) to build the new canal by selling shares in the project to domestic investors.
It is expected to more than double Suez revenues from $5.3 billion expected at the end of 2015 to $13.2 billion in 2023, officials say.
Built 146 years ago, the Suez Canal is one of the world's most heavily used shipping lanes and a key focus of international trade.