China has expressed deep sorrow over the crash of the Ukrainian passenger plane in Teheran, Foreign Ministry spokesman Geng Shuang said on Monday.

Geng conveyed condolences to the families of the victims during the daily news briefing.

All 176 people on board the Ukrainian airliner, including 82 Iranians, 57 Canadians and 11 Ukrainians, died on Wednesday when the plane crashed shortly after takeoff in Teheran.

Geng also said China has noted that relevant parties have kept in contact about the accident, and hopes the situation can be handled properly to avoid complications.

Iranian President Hassan Rouhani said on Saturday that a military probe into the tragedy concluded that missiles fired "due to human error" brought down the plane, and he called it an "unforgivable error."

The accident occurred a few hours after Iran fired missiles at two United States military facilities in Iraq. Those attacks followed a US drone strike in Baghdad on Jan 3 that killed Qasem Soleimani, commander of the Quds Force of the Islamic Revolutionary Guard Corps.

On Monday, the Iranian president issued an order to implement a law blacklisting the US Department of Defense as a "terrorist organization", according to Xinhua News Agency.

In a statement, Rouhani called on relevant Iranian organizations to implement the law, which was passed by Iran's Parliament on Jan 7. Under the new law, "all members of the Pentagon, the affiliated institutions and companies, and the US commanders who planned and perpetrated the assassination" of Soleimani are blacklisted.

The law has been endorsed by the Guardian Council of the Constitution, Iran's top legislative body.

Meanwhile, Japanese Prime Minister Shinzo Abe has been on a five-day visit that began on Saturday to Saudi Arabia, the United Arab Emirates and Oman. He is seeking cooperation to ensure stability in the Middle East and support for Japan's decision to deploy a Japanese Self-Defense Force destroyer and patrol aircraft to the region to protect Japanese ships.

Saudi Arabia, a rival of Iran's, has built good relations with the US, while Japan, which has friendly ties with Iran, has encouraged dialogue between Teheran and Washington amid a monthslong standoff over a 2015 nuclear deal.

Meeting with Abe in Al-Ula on Sunday, Saudi Arabia's Crown Prince Mohammed bin Salman expressed full support for Japan's deployment of the destroyer and patrol aircraft, according to Japanese news agency Jiji Press.

Two P-3C Orion patrol planes of the Maritime Self-Defense Force left the MSDF's Naha, Okinawa Prefecture, base in southern Japan on Saturday for an "information-gathering" mission in areas including the Gulf of Oman and part of the Arabian Sea.

The air surveillance unit has about 60 MSDF members. It will be replaced in about three months. It will start the mission on Jan 20 after arriving at a base in Djibouti and conducting drills. The MSDF destroyer Takanami is scheduled to leave for the Middle East on Feb 2, according to Jiji Press.

Tokyo chose not to join a US-led coalition outright, and will instead cooperate on information-gathering in a bid to maintain good relations with Washington and Japan's other allies. MSDF personnel will not operate in the Strait of Hormuz or further into the Persian Gulf to avoid provoking Iran, according to the newspaper Mainichi Shimbun.

In another development, the leaders of the United Kingdom, Germany and France have issued a joint statement urging Iran to fully comply with the 2015 nuclear deal, according to Japanese news broadcaster NHK.

The document, released on Sunday, expressed regret over the US' 2018 decision to withdraw from the deal, and voiced concern about the effect of further economic sanctions on Iran.

It also referred to violations of the deal by Teheran since July last year, urging Iran to reverse all measures inconsistent with the agreement and return to full compliance.

Iran announced this month that it would no longer abide by a pledge to limit uranium enrichment.