He also called for a thorough investigation, adding that "those responsible will be held accountable".
This week's meeting of the Minsk Group's security subcommittee, due in the Belarusian capital later this week, will be postponed over Sunday's blast of an OSCE mission vehicle in eastern Ukraine, a negotiator said Monday.
Austrian Foreign Minister Sebastian Kurz, who also serves as the OSCE's chairman, wrote on Twitter: "Death of colleague is a shock to whole OSCE".
The OSCE team's 600 members in eastern Ukraine are the only independent monitoring mission in the devastated industrial war zone.
Cards' Wainwright has HR, 4 RBIs in first win of season
At 35 years old, Wainwright has the zest of a little leaguer and is wise enough to know that poor season starts can be overcome. He made three appearances in rehabilitation games with Triple-A Memphis this season, allowing two runs in 14 innings.
The self-proclaimed security ministry for the Russia-backed separatist rebels in Luhansk said the mine had been laid by Ukrainian forces.
Organization for Security and Cooperation in Europe (OSCE) employees look at protesters during a rally in front the OSCE mission in Donetsk in eastern Ukraine on February 15, 2017.
"As information about this incident becomes available, it will be published on our social media channels".
NATO Secretary General Jens Stoltenberg tweeted his reaction to the incident. "Its safety and freedom of action must be guaranteed".
Egyptian-American Aid Worker, Released From Cairo Jail, Returns To U.S.
In 2015, Hijazi's mother told NPR that after her daughter was arrested, the children she used to help are "back on the streets". He added that Hijazi was set to meet Trump, along with Jared Kushner and Ivanka Trump, on Friday morning.
"The federal government expects that the parties to the conflict immediately do everything possible to ascertain how we reached this tragic point and who holds responsibility for it", she said.
An unnamed OSCE official told the AFP news agency that the explosion was "strong enough to penetrate an armoured vehicle".
A statement issued by the Lugansk separatists on their news site said the OSCE team had veered off the main road and was travelling along an unsafe route. They provide daily reports on fighting and have drawn criticism from the warring sides.
"We know that the mentioned crew deviated from the main route and moved along side roads, which is prohibited by the mandate of the OSCE SMM", the LPR press service specified.
To-Do, Wunderlist's Successor, Is Available For Public Preview
Poised as an "intelligent task management app", Microsoft To-Do is a completely new app built by the same team as Wunderlist. As is the case with a growing number of Microsoft applications and services, there's no standalone version of To-Do.
The Russian foreign ministry responded that it was "deeply outraged" by what it called a bid by undisclosed forces to undermine efforts to bring peace to its western neighbour.