In a blaze of hyper-nationalist fanfare, Egypt’s government has inaugurated an $8bn (£5.2bn) expansion of the Suez canal with an elaborate ceremony hailing the project as a national achievement.

The Egyptian president, Abdel Fatah al-Sisi, wearing his military uniform and trademark dark sunglasses in the sweltering heat, flew to the site on Thursday on board a military helicopter and immediately embarked on to a monarchy-era yacht that sailed to the venue.

The yacht was flanked by navy warships as helicopters, jet fighters and military transport aircraft flew overhead. A visibly triumphant Sisi stood on the vessel’s upper deck, waving to wellwishers and folklore dance troupes performing on the shore. At one point, a young boy in military uniform holding an Egyptian flag joined him on deck.

Later in the day, the president changed to a dark grey business suit and took his seat at the main stand for an elaborate ceremony in the canal city of Ismaïlia, attended by foreign dignitaries and organised amid tight security measures following a series of attacks by Islamic militants in the Sinai Peninsula and the capital, Cairo.

Sisi said: “Egyptians have made a huge effort so as to give the world this gift for development, construction and civilisation.” Egyptians, he said, had “showed their ability to efficiently make history and leap to the future for the prosperity of humanity”.

The ceremony to celebrate the Suez Canal expansion in Ismailia. Guardian

Among those at the ceremony were the French president, François Hollande, King Abdullah of Jordan and King Hamad bin Isa al-Khalifa of Bahrain.

The Palestinian president, Mahmoud Abbas, Kuwait’s emir, Sheik Sabah al-Ahmad al-Sabah, and the Greek prime minister, Alexis Tsipras, also attended, as well as Yemen’s exiled president, Abd Rabbu Mansour Hadi, and the Sudanese president, Omar al-Bashir.

Thursday’s ceremony was the culmination of weeks of frenzied anticipation engineered by the Egyptian state and pro-regime media. In a video broadcast on state television, a narrator said over dramatic orchestral music: “The new Suez canal changes the world map and serves humanity everywhere.”

The government claims the expansion will more than double the revenue generated by the canal, but no study has been released to the public explaining how those figures were reached. Experts say the state-sponsored pageantry surrounding the project marks it more as an attempt to stir patriotic feelings and support for Egypt’s military-backed government.

Sisi cast the canal project in the light of Egypt’s battle against violent militancy. He said: “We will continue to fight terrorism, and we will win. There is no doubt.

“Egyptians needed to feel, in a year’s time, that they have gained more confidence and security”. This was a reference to the fact that the canal expansion was completed in a year – after it was initially projected to take three. As he completed his speech, Sisi was interrupted by the low horn of a cargo ship crossing the canal behind him.

The project adds 35km of new channels on to the existing canal, which opened in 1869, and a further 35km where existing bodies of water were dredged to make way for larger ships. The Suez Canal Authority claims the expansion will lower waiting times for ships and therefore more than double annual revenue to $13.2bn by 2023. That increase would reportedly require an approximately 9% annual rise in global trade volume, a boost experts say is unlikely.

Shadi Hamid, a senior fellow at the Brookings Institution, said: “It’s not even really about economics. It’s about national pride. It’s about fighting terrorism. So it’s this one event that becomes a symbol for so many other things.

“And that’s why the regime is using it as much as it can and trying to get as much mileage out of the opening launch.”

Sisi is a former chief of Egypt’s armed forces, who led the military removal in 2013 of the then president Mohamed Morsi, an Islamist leader narrowly elected in the country’s first free elections following a popular uprising in 2011. After Morsi’s removal, the security forces killed hundreds and jailed thousands in a clampdown on political opposition.