Sinn Fein's Martina Anderson is expected to travel to Messines in Belgium next month as part of a cross-community peace initiative.
Messines was the first time the Irish and Ulster divisions fought together
The assembly member and her party colleague Willie Clarke will take part in a series of events marking the 90th anniversary of the Battle of Messines.
The 16th Irish and 36th Ulster divisions fought together for the first time during the WWI battle.
Representatives of the Irish government and some unionists will take part.
Ms Anderson said she was looking forward to the visit and acknowledged the importance of the event to "others in the community".
She said that one of her mother's uncles had fought at the battle and that she was approaching the service with an open mind.
"People fought for a multiple of reasons - and from the nationalist community too for home rule and others to put bread on the table," she said.
"But others believed it was the right thing to do."
She also said her party would be launching a "charter for unionist engagement" in Stormont on Tuesday as part of trying "to learn and understand where each other is coming from".
The attack on the Messines Ridge on 7 June began with the detonation of 19 underground mines underneath German lines.
Martina Anderson is Sinn Fein's director of engagement with unionists
The mines blew the crest off the Messines-Wytschaete ridge and was reputedly audible in Dublin and heard by Lloyd George in his Downing Street study.
Addressing his staff before the battle General Herbert Plumer said: "Gentlemen, we may not make history tomorrow, but we shall certainly change the geography."
It was later argued that the battle was the most successful local operation on the Western Front.
For the first time in the war defensive casualties actually exceeded attacking losses: 25,000 against 17,000.
At Messines, nationalist leader John Redmond's younger brother, Willie, was killed.
Although over 50 years old, he had insisted both on joining up and on serving in the front line.
"I can't stand asking fellows to go and not offer myself," he wrote.
An Irish Peace Tower was unveiled at the battle site in 1998.