BOSTON (AP) -- U.S. Secretary of State John Kerry on Tuesday condemned terrorist attacks against Israeli civilians and said that violence between Israelis and Palestinians "has got to stop."
Kerry's comments followed talks with Secretary of Defense Ash Carter and their Australian counterparts, Foreign Minister Julie Bishop and Defense Minister Marise Payne.
The officials had gathered in Boston to discuss security and trade issues, including combating Islamic extremism, the Trans-Pacific Partnership Agreement trade deal and the response to the humanitarian crises in the Middle East.
At a news conference afterward, Kerry called the situation in Israel too volatile and stressed what he called the importance of all people to avoid what he called provocative statements that can inflame tensions further.
"This violence and any incitement to violence has got to stop," he said.
Kerry said he spoke with Palestinian President Mahmoud Abbas and Israeli Prime Minister Benjamin Netanyahu over the weekend to stress his concerns.
Netanyahu said Tuesday he would take a series of "aggressive steps" to halt a wave of violence in Israeli cities after two attacks in Jerusalem left three Israelis dead. Three Palestinians, including two attackers, were also killed.
Regarding the escalating turmoil in Syria, Kerry reiterated that he believes a political solution is necessary to end a conflict that has only grown more complicated since Russia began launching attacks in the country.
Kerry said if Russia is there mostly to shore up Syrian President Bashar Assad, they will find themselves attracting more jihadis to the fight.
"There is no military solution, there is only a political solution," Kerry said. "The military component can help you get to a political solution, but Syria is literally being destroyed in that process."
Kerry said the more Assad feels emboldened by Russia's actions in the country, the less incentive he has to work toward a solution.
The CIA spent more than two years secretly working with Arab allies to arm, train and fund thousands of moderate rebels to oppose Assad. In recent days, Russia has launched a series of airstrikes targeting those groups.
Carter said he's also trying to convey that message in meetings with Russian officials that he said will also focus on the safety of pilots operating in the area.
Carter called the Russian strategy "wrongheaded and strategically short-sighted" by attempting to fight extremism without trying to support a transition to a more stable situation in the country.
Responding to a question about Jason Rezaian, the Washington Post journalist detained in Iran and convicted in secret, Kerry said that "not a meeting went by when we did not raise the issue of our citizens being held in Iran" during talks that led to a landmark nuclear deal with Iran.
He said families of those being held in Iran knew why it was important not to hold the nuclear agreement hostage to the hostages there.
"I think it was the right strategy to pursue," he said.
The meeting with the Australians focused the alliance between the two countries and on future regional and global coordination -- including in the Asia-Pacific region.
The discussions also focused on ongoing efforts to counter violent extremism, with a spotlight on the future of Afghanistan and the coalition to defeat the Islamic State group.
Kerry and the Australian officials briefly visited the finish line of the Boston Marathon, where a 2013 terrorist bombing killed three people and wounded more than 260 others.
Kerry also planned to give a talk at the Harvard Kennedy School in Cambridge.