Malaysian armed forces stand "ready" and are waiting for instructions from the top leadership if they need to play a role after the US President Donald Trump recognised Jerusalem as Israel's capital, said the country's defence minister.

Hishammuddin Hussein said the Muslim-majority nation's military should be prepared for any repercussions emerging from the decision, which has sent shockwaves across Muslim nations and attracted widespread condemnation. Hussein, however, did not elaborate on why the military was in a state of readiness. But he insisted Trump's decision was a "slap in the face for the entire Muslim world".

"We have to be prepared for any possibilities. The ATM [Malaysian Armed Forces] has always been ready, waiting for instructions from the top leadership," said the defence minister.

Malaysia was among dozens of countries which vociferously condemned Washington's decision to unilaterally consider Jerusalem – a city considered holy by both Israelis and Palestinians – as the Israeli capital. President Donald Trump's announcement had triggered a series of angry responses not just from the volatile Middle East but also from other continents, Europe and Asia.

While Israel regards entire Jerusalem, which is at the heart of the Israel-Palestine conflict, as its capital, Palestinians hope East Jerusalem will one day become their capital when a state of Palestine is formed in the future.

"Let us pray that this dispute would not lead to chaos," said Hussein.

In neighbouring Indonesia, which has the world's largest population of Muslims, thousands had gathered outside the American diplomatic mission in Jakarta to protest against the move.

Earlier, Malaysian Prime Minister Najib Razak had called for unity in the Muslim world to rally against the US move. "If the world is united, there is hope in foiling the US proposal to make Jerusalem the capital of Israel. As an Islamic country, it is very important that we engage in any action to save Jerusalem."

The Malaysian defence minister's comments come shortly after his Israeli counterpart had called for a boycott of Arab citizens and Arab-run business in the tense Wadi Ara region in northern Israel over simmering protests in the area.

"They [the anti-Israel and anti-US protesters] should understand that they are not wanted here, they are not part of us," said Avigdor Lieberman, before adding that the residents of Wadi Ara "have no connection to this country".