国际英语新闻:Putin, Obama Discuss Security Cooperation

Officials in Russia say President Vladimir Putin and U.S. President Barack Obama have agreed to increase contacts between their countries' intelligence agencies following the Boston Marathon bombings.

The two leaders spoke by telephone Monday. The White House says President Obama reiterated his appreciation for the close cooperation that the United States has received from Russia on the Boston attack.

The White House also says the two presidents will hold a bilateral summit in Russia in September.

U.S. and Russian officials say the leaders discussed future cooperation on security, including the 2014 Winter Olympics, which will be held in the Russian city of Sochi.

In addition, the White House says they reviewed the situation in Syria, with President Obama underscoring his concern over Syrian chemical weapons.

Last week, the White House said U.S. intelligence agencies believe with "varying degrees of confidence" that the Syrian government has used sarin gas on a small scale against Syrian rebels.

Boston bombing suspects Tamerlan and Dzhokhar Tsarnaev are Russian natives who immigrated to the Boston area. Russian officials contacted U.S. intelligence agencies more than two years ago to express concerns about the family. But a U.S. inquiry at the time was closed in late spring of 2011.

A few days ago, Russian authorities told U.S. investigators they had secretly recorded a 2011 phone conversation in which Tamerlan's mother, Zubeidat Tsarnaeva, had vaguely discussed jihad with her son.