The statement confirms an earlier plan to vote on the nomination.
The move to reject the German defence minister, 60, from taking over Jean-Claude Juncker's role could plunge the European Union into a fresh crisis.
Von der Leyen, a 60-year-old former gynaecologist and mother of seven, switched between English, French and German as she spoke in favour of enlarging the eurozone and the EU's open-border Schengen area, provided countries meet the criteria.
"What she will do concretely is unclear", he added.
Environmental groups are not the only ones concerned about von der Leyen's capacity to deliver the social and environmental justice citizens demand. Von der Leyen needs the backing of an absolute majority of 376 votes in the 751-strong chamber to get confirmed as president of the European Commission.
Germany's Ursula von der Leyen yesterday made her pitch to European lawmakers to be the next head of the EU executive, promising to focus on promoting the rule of law, digitalisation, competitiveness and the fight against climate change. But she needs more votes.More news: NASA chief shakes up moon program management
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"Everything is split here", said one parliament source.
The political groups could also use their leverage to obtain concessions on policy priorities or personnel appointments, and delay the confirmation vote for weeks or even months, as that the current Commission remains in place until November.
"I think it's a good deal, but it is your responsibility and your noble task to sort this out", she told a British Liberal Democrat MEP in the European parliament, in her first public comments on Brexit.
European leader backed von der Leyen ahead of the EPP's official nominee Manfred Weber, as well as socialist Frans Timmermans and liberal Margrethe Vestager, who have now both been proposed as Commission Vice-Presidents.
Legislators wanted one of the lead candidates of the groups to become European Commission president, but that initiative was scuttled by leaders under pressure from France, Italy and several eastern member states.
Ursula von der Leyen has been highly critical of Beijing's record on human rights and personal freedom and has accused the Chinese regime of carrying out economic cyber-attacks in Western countries.
Defending the package and the legitimacy of the heads of state's choice, European Council President Donald Tusk stressed that, for the first time, the EU achieved a flawless gender balance in the top positions. "And the political consequences are way harder when it comes the other way round".