His remarks come as the U.S. ratchets up its hostile posturing aimed at Iran.
"The administration is lying to the American people when they say it was an unprovoked attack", Kaine said, arguing the USA imposed sanctions and other withdrawal from the Iran nuclear deal are provoking Iran's behaviour.
In retaliation for the U.S. "maximum pressure" policy, Iran has gradually scaled backed its commitments to the pact and plans to further breach it if the European parties fail to keep their promises to shield Iran's economy from USA penalties.
President Trump is "obligated to try and find peace", he said.
"I'm somebody that would like not to have war", he said. Pompeo and others will travel to Saudi Arabia soon, Trump said.
Speaking to reporters in London, Dunford noted - as Trump had on Monday - that the attack was not aimed at the United States or US forces.
He said at the White House that the USA is not looking at retaliatory options until he has "definitive proof" that Iran was responsible. "But when we have a definitive on that we'll let you know".
The attack resulted in the suspension of approximately 50 percent of Saudi Aramco's production and was initially blamed on Houthi rebels from neighbouring Yemen.
Iran's Foreign Ministry spokesman Abbas Mousavi dismissed Washington's accusations, calling them "blind and futile".
Oil prices surged by as much as 19% after the incidents but later came off their peaks. But U.S. officials are blaming Iran.
In Congress, Republican Senator Mitt Romney told reporters that the United States should not be drawn into war.
Riyadh says its stockpiles will keep world markets supplied until it can fix the damage at Abqaiq and Khurais.
The Biggest Winner In The Saudi Oil Supply Crisis
The Persian Gulf region has witnessed greater unrest since Trump's decision past year to abandon a 2015 nuclear deal with Iran. Separately, other US officials say the evidence that already has been collected is conclusive and points directly to Iran.
"The kingdom is capable of defending its land and people and responding forcefully to those attacks", the statement added.
Other military analysts have speculated about launch sites by Iran-linked militias in Iraq.
But Mr Trump said he had not made commitments to protect the Saudis.
German Chancellor Angela Merkel said the Iran nuclear pact, which European parties are trying to salvage, is one building block "we need to get back to".
Will the attacks on Saudi oil facilities cripple global supplies? Earlier estimates had suggested it could take weeks.
"Tensions have risen since last weekend's drone strikes on Saudi Arabia's oil facilities". At least 11 supertankers were waiting to load oil cargoes from Saudi ports, ship tracking data showed on Monday. Iran has denied any involvement.
Saudi Arabia and Iran have been enemies for decades and are fighting a number of proxy wars, including in Yemen where Saudi forces have been fighting against the Houthis for four years.
The Iranian president and foreign minister are going to attend an annual meeting of the United Nations general Assembly in NY later this month. Iran says there can be no talks until Washington lifts sanctions. The kingdom, though, has not yet said where the attack was launched from or what kind of weapons were involved.
But he also promised to apply fresh pressure on Iran, a pledge complicated by the latest apparent provocation.
"We assure the Saudi regime that our long arm can reach any place we choose and at the time of our choosing", Sarea tweeted. "What is Iran's calculation here, and do they have a Plan B?"
Minister Prince Abdulaziz bin Salman also told a news conference that the world's top oil exporter would keep full oil supplies to customers this month.
Riyadh asked worldwide experts to join its investigation, which indicates the attack did not come from Yemen, the foreign ministry said.