AFP - Israeli Prime Minister Benjamin Netanyahu travelled to Portugal Wednesday to meet US Secretary of State Mike Pompeo and call for increased pressure on the "tottering" Iranian government.

The two men will meet on Wednesday night in Lisbon, the US State Department announced.

Speaking before setting off, Netanyahu said US President Donald Trump's sanctions against Iran were paying dividends and he would be urging Pompeo to take further steps.

"I think President Trump has placed tremendous pressures and sanctions on Iran," he said.

"We're seeing the Iranian empire totter. We see demonstrations in Tehran, demonstrations in Baghdad, demonstrations in Beirut. It's important to increase this pressure against Iranian aggression."

Israel, which has the Middle East's sole but undeclared nuclear arsenal, has for years accused Iran of seeking to obtain nuclear weapons and strongly opposed a 2015 agreement designed to address the concerns of major powers.

Trump, a strong Netanyahu ally, unilaterally pulled the United States out of the deal in May last year and reimposed crippling sanctions.

Netanyahu, who is fighting for his political life after an indictment on graft charges, has hailed the Trump sanctions.

Israel believes they have squeezed the Iranian economy, prompting the government to raise fuel prices -- sparking nationwide protests.

Lebanon and Iraq, both countries where Iran has significant influence, have also seen major demonstrations.

Netanyahu criticised European governments that have signed up to a barter system that would allow Iran to trade without fear of US sanctions.