Prime Minister Benjamin Netanyahu will visit Europe before the end of the year in an effort to persuade leaders to step up sanctions on Iran over its nuclear program.

Netanyahu told the United Nations last week that Iran will likely have to be stopped by next summer, by when it would have amassed enough 20-percent enriched uranium for a bomb. He has said he does not rule out a military strike.

After unsuccessfully lobbying US President Barack Obama’s administration for support for such a strike — or for an American declaration that Iranian activity beyond a certain “red line” would invite US military intervention — Netanyahu’s plans for a European trip to push for tighter sanctions on Tehran seem to signal a shift in policy.

The Foreign Ministry recently issued a report concluding that sanctions are hitting Iran hard, and urging the imposition of more. It was reported Tuesday night that Israeli embassies in Europe have been told to reach out to European governments to encourage support for wider sanctions against Iran.

Israel’s Deputy Prime Minister Moshe Ya’alon said Tuesday that sanctions were plainly impacting the Iranian economy — with the Iranian rial falling to new lows against the dollar this week — but that they had yet to prompt Iran to slow its drive toward the bomb.

The New York Times on Tuesday quoted an unnamed Israeli official as saying, “Our feeling is that with the elections and everything, we’ve not seen much on the American front except for sealing holes where the Iranians have found ways to get around the sanctions.”

Regarding the shift to Europe, the official said, “Up until now, it’s been the US and then the Europeans following. If it’s the other way around, so be it. We’ve got to go with what we’ve got.”

He added, “Personally, I don’t think we’ll get a full trade embargo, but it’s always good to aim high and see what comes out of the wash.”