RIYADH/DUBAI — The US ambassador to Saudi Arabia said Washington should take what he called "reasonable responses short of war" after it had determined who was behind attacks on oil tankers off the coast of the United Arab Emirates.

Iran was a prime suspect in the sabotage on Sunday although Washington had no conclusive proof, a US official familiar with American intelligence said on Monday.

"We need to do a thorough investigation to understand what happened, why it happened, and then come up with reasonable responses short of war," Ambassador John Abizaid told reporters in the Saudi capital Riyadh in remarks published on Tuesday.

"It's not in (Iran's) interest, it's not in our interest, it's not in Saudi Arabia’s interest to have a conflict."

Four commercial vessels, including two Saudi oil tankers, were sabotaged on Sunday near Fujairah, one of the seven emirates of the UAE and a bunkering hub just outside the Strait of Hormuz.

Washington has increased sanctions on Tehran, saying it wants to reduce Iranian oil exports to zero, after quitting the 2015 nuclear pact between Iran and global powers last year.

The US Maritime Administration said last week that Iran could target US commercial ships including oil tankers sailing through Middle East waterways. Tehran has called the US military presence "a target" rather than a threat.

US Secretary of State Mike Pompeo shared information on what he called escalating threats from Iran during meetings with EU counterparts and the head of NATO in Brussels on Monday, the US special representative for Iran Brian Hook said.

Hook declined to say whether he believed Iran played a role in the attacks off Fujairah or if Pompeo blamed Iran. He said the UAE had sought US help in the investigation.

Saudi Arabia's energy minister said on Monday that the attack aimed to undermine security of global crude supplies.

A fifth of global oil consumption passes through the Strait of Hormuz from Middle East crude producers to markets in Asia, Europe, North America and beyond. The narrow waterway separates Iran from the Arabian Peninsula. — Reuters