PARIS (Reuters) - French far-right leader Jordan Bardella said on Wednesday that he backed Ukraine's right to defend itself against Russia, but if elected prime minister he would not provide Kyiv with missiles that would allow it to strike Russia's territory.

He also said he would standby France's commitments to the NATO military alliance if he became prime minister.

Bardella's National Rally (RN) party leads opinion polls ahead of June 30 and July 7 snap parliamentary elections, which has led to questions over the foreign policy implications if they win enough seats to form a government.

"I wish for Ukraine to have at disposal the ammunition and equipment it needs to hold the front, but my red line will not change, which is sending equipment that could have consequences of escalation in eastern Europe," Bardella told reporters at the Eurosatory arms fair near Paris.

"And so I don't plan to send, especially, long-range missiles or other weapons that will allow Ukraine to strike the Russian territory. My position has not changed and will not change - it's about support for Ukraine and avoiding all risks of escalation in the region. And I think the risk of escalation is of course real."

Even if the RN was to run France's government, Emmanuel Macron would remain as president, and the head of France's army.

But the constitution also gives the prime minister a role in terms of defence, with the division of power not clear cut.

Macron would lose control over the domestic agenda, including economic policy, security, immigration and finances, which would in turn impact other policies, such as aid to Ukraine, as he would need parliament's backing to finance any support as part of France's annual budget.

Bardella also said he would keep France's commitments towards its partners, including on increasing defence spending.

"I don't plan to put into question the commitments made by France on the international level, because there's a stake regarding credibility towards our European partners as well as towards our NATO allies," he said.

"And so I plan to pursue the efforts of rearmament of the country, both in terms of its defence capabilities, increasing the military budget through budgetary efforts put in place in past years, which we have supported," he added.

(Reporting by Ardee Napolitanno; writing by Sudip Kar-Gupta; editing by Ingrid Melander and Sharon Singleton)