Addressing a press conference with Netanyahu, whose aim during the two-day visit is to press for more pressure on Tehran, Hollande warned that Paris would back "other sanctions" if Tehran failed to convince on its contested nuclear programme.
"This is a threat which cannot be accepted by France," Hollande said.
"We have voted for many sanctions and are ready to vote others as long as necessary," the French leader said, underscoring that he wanted "proof that Iran has abandoned this drive."
Iran denies Israeli and Western suspicions that its nuclear programme is a front for a drive for a weapons capability.
Netanyahu hailed the "extremely important position" taken by Hollande.
Netanyahu has warned that a nuclear Iran would pose an existential threat to the Jewish state and has repeatedly refused to rule out military action, fuelling speculation that an attack was imminent.
But he then appeared to pull back, pushing the deadline until spring or even summer 2013, ostensibly to allow time for international sanctions to work.
The pugnacious Israeli leader said in an interview Wednesday that the Arab world would be relieved if Israel struck at Iranian nuclear facilities.
He said in case of an attack, "five minutes later, contrary to what sceptics think, I believe there will be a great feeling of relief throughout the region."
"Iran is not popular in the Arab world, far from it," he said in comments reported in French in France's Paris-Match weekly.
"And some neighbouring regimes and their citizens have well understood that a nuclear-armed Iran is a danger for them, not only for Israel," he said, without mentioning specific nations.
Hollande meanwhile urged Israel and the Palestinians to resume peace talks without any conditions, while criticising continued Israeli occupation.
"Only negotiations can lead to a definitive solution," he said. "These negotiations are hoped for and awaited."
"France wants the resumption of talks between Israel and the Palestinians without conditions and with the same goal – one we have been pusuing for years, even decades, two states, a state of Israel where security if guaranteed and a Palestinian state which must be allowed to live," he said.
Hollande said the two countries had "divergences on occupation, which we want to see halted."
Direct peace talks have been on hold for more than two years, with Palestinian president Mahmud Abbas refusing to negotiate as long as Israel continues to build and approve new Jewish settlements.
Netanyahu is hoping during the two-day trip "to build a good working relationship with the French leader," a source close to the Israeli leader told AFP.
Since taking office five months ago, Hollande has only spoken to Netanyahu by telephone but met Palestinian president Mahmud Abbas twice – both times in Paris.
Netanyahu enjoyed close ties with Hollande's predecessor Nicolas Sarkozy who cast himself as a "friend of Israel" but there was a chill after Sarkozy reportedly called him a "liar" in November last year during a private conversation with US President Barack Obama.
On Thursday, Netanyahu is to travel to Toulouse with Hollande to attend a memorial ceremony for three children and a French-Israeli teacher at a Jewish school who were shot dead by an Islamist gunman who also killed soldiers of North African origin.
The Israeli prime minister also evoked rising anti-Semitism, which he said was a "threat for all the European people."
But Hollande pledged to "eradicate" attacks on Jews in France, saying: "Whenever a citizen's security is challenged just because he is Jewish – it's the Republic which is attacked."
The two leaders then launched into a light-hearted exchange with Netanyahu urging French Jews to settle in Israel and Hollande responding that their place was really at home.
France is home to between 350,000 and 500,000 Jews, according to various estimates. Since the creation of Israel in 1948, more than 90,000 French Jews have settled there.
Demonstrations against Netanyahu's visit are planned in several French cities.