Missile strikes overnight in central Syria killed at least 26 pro-regime fighters, most of them Iranians, a monitor said Monday.
"Our priority as an international community remained preventing Iran from developing a nuclear weapon," Downing Street said.
A Saudi-led military coalition intervened in Yemen on March 26, 2015 to try to restore the government of President Abedrabbo Mansour Hadi.
North Korea has called off a joint cultural performance with artistes from the South ahead of the forthcoming Winter Olympics, Seoul said on Monday, underscoring the fragility of their Games-led rapprochement.
Israel also fired ground-to-ground rockets from the Israeli-occupied Golan Heights, but the Syrian defences brought the missiles down, the Syrian army said.
Speaking on a visit to Japan, Secretary-General Antonio Guterres said: "The worst possible thing that could happen would be for us all to sleepwalk into a war that might have very dramatic circumstances."
Iran will strengthen its missile capabilities and will not seek any country's permission, President Hassan Rouhani said on Friday in a snub to demands from US President Donald Trump.
Guam officials were "ecstatic" on Tuesday as North Korea appeared to back away from its threat to fire four missiles towards the US territory in the western Pacific.
Guam residents say that if given the choice they would rather face the wrath of ‘crazy’ Kim Jong Un than the power of a typhoon, as they count down towards a threatened North Korean missile attack.
Nuclear-armed North Korea said Tuesday its missile launches were training for a strike on US bases in Japan, as global condemnation of the regime swelled.