Johnson is expected to win the contest to replace outgoing Prime Minister Theresa May at the end of July.
Russia has repeatedly criticized President Donald Trump's administration for its aggressive stance towards Tehran.
The bombastic president said he would be willing to support Washington if war broke out with Beijing in the South China Sea.
A leading opponent to the Iran nuclear deal, Israel has now threatened to go to war if Tehran does not abide by its restrictions.
Foreign Minister Sergey Lavrov said a military conflict between Washington and Tehran would be an "international crisis."
Trump's freewheeling remarks to reporters came after the president made the last-minute decision to call off an approved airstrike on Thursday
Wednesday's drone shoot down is the latest in a series of escalations that threaten to push Washington and Tehran into open conflict.
The Pentagon is still investing in "deeply flawed" strategies to the detriment of national security, said the Center for New American Security report.
President Donald Trump frequently reminds us that "all options are on the table" in enforcing U.S. policy, could that lead to war in Iran, North Korea, Syria, Ukraine or Venezuela?
President Trump and Iranian leaders insist they don't want war. But with a build-up of military might on both sides and increasing economic pressure from the U.S., tensions remain high
President Donald Trump's administration has created a potent anti-Iranian alliance in the Middle East.
"We remind the U.S. not to underestimate China's ability to defend its rights to development and to remember not to blame anyone for not warning them," the Communist Party's paper warned.
American imports from Vietnam rose 40.2 percent in the first three months of the year.
"These farmers are going to end in bankruptcy, and committing suicide and losing their farms and they're still talking about supporting the president," the president of the National Black Farmers Association said.
Previous reports suggested the main responsibilities of about 1,500 additional U.S. troops would be "defensive in nature."
President Donald Trump threatened "the official end of Iran" in a tweet days earlier.
"Washington is deliberately provoking Iran," Russian Foreign Ministry spokesperson Maria Zakharova claimed.
Despite Norwegian and U.S. denials, the Globus-II radar previously served in a role related to missile technology and was once revealed to be pointing toward Russia.
Trump won't get far unless he "moves away from maximalist demands and demonstrates that he can be a credible partner in diplomacy," said Arms Control Association's Kelsey Davenport.
"They're not going to change their system, and I think a lot of hard-liners in the Trump administration are looking for them to do that," said Stephen Roach, a veteran Wall Street analyst.
The Pentagon is reportedly preparing to present plans to send 10,000 more troops to the region.
One paper found tariffs are costing U.S. consumers and businesses $3 billion per month in added tax costs.
Venezuelan President Nicolás Maduro said the talks had a "peaceful agenda," but national security adviser John Bolton said "his exit" was "the only real solution."
"#WeHaveTheWatch," the North American Aerospace Defense Command (NORAD) tweeted.
"I hope that the Iranian people demand better leadership, but we'll have to wait and see," the senator told Fox News.
"We are now embarking on a new Long March, and we must start all over again," Chinese President Xi Jinping said.
Iran's top diplomat said his country was not interested in escalation, but Iranians "will defend ourselves" and such an escalation would mean "painful consequences" for both sides.
"Unless there is a de-escalation of trade tensions, the outcome could be much worse than in our central scenario," said the secretary-general of the Organization for Economic Cooperation and Development.
Mainland Alaska and mainland Russia are only roughly 55 miles apart, and the two share a chain of islands known as the Aleutian Islands, meaning such incidents are not unprecedented.
Alexander Bortnikov, head of the Federal Security Service, warned that 5,000 fighters from ISIS had been deployed in northern Afghanistan.