BUCHAREST -Romanian President Klaus Iohannis said on Thursday he was withdrawing his bid for NATO's leadership, clearing the way for Dutch Prime Minister Mark Rutte to become the alliance's secretary-general.

Romania will back Rutte and donate one of its two operational Patriot missile systems to Ukraine on condition that allies replace it with a similar air defence system, Bucharest's Supreme Defence Council (CSAT) chaired by Iohannis said.

It had made the decision to donate the Patriot system "considering the significant deterioration of Ukraine's security situation following constant and massive attacks by Russia on civilians and civilian infrastructure as well as ... the regional consequences including on Romania's security," CSAT said in its statement.

Iohannis had notified NATO about the withdrawal of his candidacy last week, the statement added.

NATO takes decisions by consensus, so any candidate needs the support of all 32 allies. Only Romania had still been officially opposed to Rutte's candidacy.

Rutte, a staunch ally of Kyiv and a critic of Russian President Vladimir Putin, had been seen as set for the job since Tuesday when Hungary and Slovakia dropped their resistance.

NATO's next secretary-general will face the challenge of sustaining allies' support for Ukraine's fight against Russia's invasion, while guarding against any escalation that could draw the military alliance directly into a war with Moscow.

Iohannis, whose second term as Romanian president ends later this year, has repeatedly said Eastern European states need better representation in Euro Atlantic leadership roles.

European Union and NATO state Romania has raised defence spending to 2.5% of gross domestic product in response to Russia's invasion of Ukraine.

It signed a $4 billion deal to get Patriots in 2017, the country's biggest procurement contract to date, with the first shipment delivered in 2020.

  - Reuters