"There are also other parties in the European Union or Europe that we would like to work together with," Wilders said, acknowledging that one of the highest-profile Euroskeptic groups, the United Kingdom Independence Party led by Nigel Farage, was not yet ready to join forces.
Wilders said he hoped the UKIP would be prepared to join their alliance after European elections scheduled for late May.
The EU's economic malaise has fueled a rise in Euroskepticism among voters who question whether the grand idea of one continent, one market, one currency is capable of delivering prosperity for all. Some are also growing increasingly frustrated at what they see as too much devolution of national powers to EU bureaucrats in Brussels.
Wilders' party has long advocated that the Netherlands should pull out of the EU altogether. Le Pen says France should hold a referendum on the issue.
Standing next to one another at a packed press conference in The Hague, both acknowledged that their parties do not agree on everything.
In the past, Wilders has been reluctant to associate his party with the National Front, because of controversial comments by its founder Jean-Marie Le Pen, Marine's father.
Jean-Marie Le Pen has been convicted and fined for racism and anti-Semitism, but his daughter has sought to soften the party's message and turned its anger toward what she calls the "Islamization" of France.
That brings the National Front more closely into line with Wilders' PVV, which is pro-Israel and outspokenly anti-EU and anti-Islam. Wilders has called for a halt to building mosques in the Netherlands and for a ban on the Quran.
About 30 protesters, watched over by dozens of police, staged a noisy protest against Le Pen's visit on a square outside parliament on Wednesday.
Wilders is a polarizing figure in the Netherlands, attracting adulation from supporters and death threats from a tiny section of his opponents. He has for years lived under round-the-clock protection because of those threats.
Tony Brown, a board member of Ireland's Institute of International and European Affairs, questioned whether groups with strongly nationalistic backgrounds from across Europe will be able to work together successfully, but said they could form a new voice at the European Parliament despite their limited numbers.
At the moment, the PVV has four seats in the European Parliament and the National Front three, but they do not sit together in the 766-seat legislature.
Even assuming both Euroskeptic parties make gains in May, they will likely remain dwarfed by Europe's established political groups. Currently the largest two blocs at the European Parliament are the center-right European People's Party, made up of Christian Democrats, which has 275 seats, followed by the center-left Progressive Alliance of Socialists and Democrats, which has 194 seats.
