Israel's National Security Adviser Yaakov Amidror is holding talks with European officials ahead of the next round of talks over Iran's disputed nuclear programme, a newspaper reported on Tuesday.
The report, in the left-leaning Haaretz daily, said Amidror's trip was linked to Israeli concerns that the talks between Iran and the P5+1 group of world powers could ultimately end with a deal that would allow Tehran to continue enriching uranium.
Israeli officials refused to comment on the report.
The P5+1 grouping of diplomats from the United States, Russia, China, Britain, France and Germany, held a first round of talks with Iran on April 14 in Istanbul with a second round due to take place in Baghdad on May 23.
Haaretz said Amidror arrived in Brussels on Monday and held talks with Helga Schmid, the EU deputy secretary general for political affairs, who is responsible for preparatory talks with Iran ahead of the Baghdad meeting.
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Amidror was expected to travel on Wednesday to Berlin where he was to meet top German officials, among them Hans-Dieter Lucas, Germany's representative to the Iran talks, the paper said.
Two weeks ago, Amidror was in Moscow for similar talks and met Foreign Minister Sergei Lavrov, Haaretz said.
Israel has consistently warned that a nuclear-armed Iran would pose an existential threat to the Jewish state, and has refused to rule out a pre-emptive strike in a bid to halt it.
And top officials have expressed doubt the talks would be effective, with Prime Minister Benjamin Netanyahu last month criticising the Istanbul meeting as having little impact, and effectively giving Tehran "a freebie" to continue enriching uranium.
And on Monday, Defence Minister Ehud Barak also said he had little confidence the talks would succeed.
"The P5+1 engagement with Iran, however, does not fill me with confidence. I may sound pessimistic but the state of Israel cannot afford to be duped," he told journalists at a meeting of the Foreign Press Association in Jerusalem.
Israel is concerned that the world powers may cut a deal with Iran that would have only a limited impact on its nuclear programme in exchange for an easing of sanctions, Haaretz said.