Military hardware will be paraded through the streets of central Kiev on Sunday as part of events to mark Ukraine's Independence Day, which has become steeped in controversy because of the fighting still raging in the east.

Critics have denounced the Kiev parade – which will also feature 1,500 servicemen marching – as a waste of money and a dangerous diversion while the country is at war. Others have suggested a celebration of military might is inappropriate at a time when Ukrainians are dying, as fighting continues in the eastern regions of Donetsk and Luhansk.

However, supporters say the parade should boost morale in Ukraine's army, which has been bogged down in the fight against Russia-backed separatists for three months.

Sunday is the 23rd anniversary of Ukraine's independence after the Soviet Union collapsed, and there will be parades in both Kiev and Odessa.

The soldiers will be joined by around 90 new military vehicles in central Kiev, including Grad multiple rocket launchers, surface-to-air missile systems and ballistic missile systems. Grad missiles have been particularly controversial in the current conflict in the east, given their lack of accuracy. Human Rights Watch has accused both the government forces and the separatists of using Grads against residential areas.

Sunday's celebration, a day after the German chancellor, Angela Merkel, is due to visit Kiev, will begin with a prayer for Ukraine and the laying of wreaths for all those who died in the name of independence, including this year the Heavenly Hundred, the term for the people killed during the Maidan street protests in Kiev last winter.

President Petro Poroshenko has ordered a 20-gun military salute in Kiev and Odessa and fireworks displays all around the country. It will be the first military parade since 2009, as they were scrapped during the rule of Viktor Yanukovych, who is now hiding in Russia.

Volunteer Oksana Chorna, who regularly travels to the conflict zone to supply the army, said her friend was proud to be chosen as one of the 120 servicemen fighting in the east who will participate in the Kiev parade. "The best fighters were gathered and they will walk down Khreschatyk Street [Kiev's main thoroughfare]. This is very important for them," Chorna said. "And the civilians also need to be reminded that there is actually a war going on."

The prominent writer Oksana Zabuzhko said the celebration of Ukraine's independence would be crucial "amid the war for independence", as it should unite the nation. "There is no army without parades, and for the army, which is fighting a war, it is doubly important from a moral and symbolic stance," she wrote on her Facebook page.

But critics say any celebrations are an insult when Ukrainian soldiers are dying in fighting, often due to poor equipment and armaments. According to official figures released this month, 568 Ukrainian servicemen have been killed and more than 2,120 injured since the beginning of hostilities.

The army has been augmented with volunteer battalions made up of former Maidan protesters or simply volunteers, many of whom have questionable levels of training. Volodymyr Parasiuk, a prominent former Maidan protester who now heads a unit of the Dnipro volunteer battalion, said it was not a good time to celebrate when the war was yet to be won. He said the country should care more for its soldiers instead.

"If the authorities and generals want to demonstrate [military] vehicles they would better go to the east and see what are our guys are fighting with," Parasiuk told local media.

About a dozen activists picketed the presidential administration on Wednesday demanding the parade be cancelled at a time when the country is hugely reliant on volunteers to supply its army. Since the end of July, Ukrainians had paid 1.5% of their salaries as a special war tax to boost the financing of the troops.

Despite officials' insistence that the new vehicles would be sent to the conflict zone just after the parade, many believe they need to be sent there immediately and that even the use of fuel for the parade is an unnecessary waste.

"Every day when there's nothing to cover the infantry it means losses. So a price of the parade will be lives of Ukrainian soldiers," Ihor Lutsenko, a former Kiev activist and now a deputy on the city council, wrote on his blog.