UNITED NATIONS, July 18 -- The United Nations political chief said Friday that the downing of Malaysian Airlines flight MH17 on Thursday in eastern Ukraine with nearly 300 people onboard highlighted the need for an urgent resumption of a ceasefire and a serious effort to end the ongoing Ukraine crisis.

"This horrifying incident serves as the starkest reminder of how dire the situation in eastern Ukraine has become -- and how it affects countries and families well beyond Ukraine's borders," UN Under-Secretary-General for Political Affairs Jeffrey Feltman said at an emergency meeting of the Security Council on the disaster.

Feltman said while security, political, economic, social, and human rights issues in Ukraine that should be addressed are complicated, it is hoped that the shock of the downing of the passenger jet will prompt a "serious and sustained" effort to end the fighting.

He said that following the June 30 announcement by President Petro Poroshenko of the end to a 10-day ceasefire and subsequent resumption of the security and law enforcement operation in the eastern parts of Ukraine, the fighting between government forces and armed groups has intensified dangerously, resulting in numerous deaths.

"As the secretary-general has reiterated on countless occasions, armed groups need to immediately disarm and stop engaging in unlawful and violent acts," Feltman noted. "At the same time, we continue to strongly urge the Ukrainian authorities to act with maximum restraint and to make every effort possible to ensure the protection of civilians caught in the fighting."

The UN political chief stressed that "a first, critical step would be the immediate resumption of a ceasefire."

"Establishing a path to peace in Ukraine, as in areas of conflict elsewhere in the world, requires a concerted effort by national actors from across the political spectrum, backed by strong and unified support of the international community," said Feltman, who is expected to travel to Kiev and Moscow in the coming days.

Before the emergency meeting, the Security Council issued a press statement calling for a "full, thorough and independent" international investigation into the MH17 incident and for " appropriate accountability."

"The members of the Security Council further stressed the need for all parties to grant immediate access to investigators to the crash site to determine the cause of the incident," said the statement.

At the start of the meeting, the Security Council members stood for a minute of silence for those who lost their lives in the Thursday crash.

Feltman said the UN is fully ready to cooperate, and it has been in touch with the UN International Civil Aviation Organization, which has offered to Ukrainian officials its investigative capacity in order to put together an international team.

Among the casualties of the crash was a staff member of the World Health Organization (WHO), Glenn Thomas, who was on his way to an international AIDS conference in Australia, he said.

Malaysia Airlines flight MH17, a Boeing 777-200, was en route from Amsterdam to Kuala Lumpur when it went down Thursday in eastern Ukraine with 298 passengers and crew aboard, according to Malaysian Airlines.

No survivors have been found on the crashed plane.