The Foreign Office (FO) on Monday expressed "grave concern" on the opening of a US embassy in Jerusalem, which it deemed "a violation of international law and several United Nations Security Council resolutions".

The United States today had officially inaugurated its deeply controversial Jerusalem embassy in a ceremony that included a video address by President Donald Trump.

Meanwhile, deadly clashes left 52 Palestinians dead from Israeli fire and more than 2,400 wounded.

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"Pakistan has noted with grave concern that despite calls by the international community to comply with the UN General Assembly and Security Council resolutions on the two-state solution, the US is moving its embassy to the holy city of Jerusalem," the FO said.

"This represents a violation of international law and several United Nations Security Council resolutions, in particular resolutions 476 and 478.

"The government and people of Pakistan stand firmly with the Palestinian people."

Meanwhile, Turkey President Recep Tayyip Erdogan also condemned the US decision to move its Israel embassy to Jerusalem.

The Turkish president said the US disregarded “rights and justice,” ignoring the international community.

Erdogan says the move serves to “reward” the Israeli government despite it undermining efforts to resolve the decades-long conflict, while it “punished” Palestinians.

“History and humanity will never forgive the injustices done to our Palestinian brothers,” he added.

Iran's Foreign Minister Mohammad Javad Zarif called the opening of the US Embassy in Jerusalem “a day of great shame.”

“Israeli regime massacres countless Palestinians in cold blood as they protest in the world's largest open air prison," he said. "Meanwhile, Trump celebrates move of US illegal embassy and his Arab collaborators move to divert attention.”

UN Secretary-General Antonio Guterres expressed his concerns as clashes were taking place along the Israeli-Palestinian border, saying: “I'm particularly worried about the news coming from Gaza with the high number of people killed.”

Russia's Deputy Foreign Minister Mikhail Bogdanov described the relocation of the embassy as “short-sighted.”

Bogdanov said in an interview with the Interfax news agency that the decision “runs against the stance of most of the international community.”

He blamed the US for “a sharp escalation around Gaza” and said the relocation of the US embassy “could spark large-scale confrontations between Palestinians and the Israelis and cause a rising number of casualties.”

Lebanese Prime Minister Saad Hariri called the move a “provocative” act that closes the doors for any attempts to reach peace between the Israel and Palestinians.

The Cairo-based Arab League called on the international community to oppose what it considers an “unjust decision” and the ongoing “Israeli occupation” of the city.

It called the move a “blatant attack on the feelings of Arabs and Muslims,” and a “grave violation of the rules of international law” that would destabilize the region.

Egypt's Al-Azhar religious institution called on the international community to use “all peaceful means” to “dismiss positions of countries that sided with the Zionist entity,” referring to Israel.

European foreign ministers say the U.S. decision to move the American embassy to Jerusalem is unwise and likely to exacerbate tensions.

Irish Foreign Minister Simon Coveney said that the move “is inflaming already a very tense situation, and the relationship between Israelis and Palestinians.”

His Dutch counterpart, Stef Blok, said “we don't consider it a wise decision to move the embassy.”