Obama has canceled plans to meet with Russian President Vladimir Putin, the AP reports:

The move is in retribution for Russia's decision to grant temporary asylum to National Security Agency leaker Edward Snowden. But it also reflects growing U.S. frustration with Russia on an array of other issues, including missile defense and human rights.

Obama still plans to attend the G20 summit in St. Petersburg but will not meet privately with Putin there either.

UPDATE: White House Press Secretary Jay Carney released the following statement:

Following a careful review begun in July, we have reached the conclusion that there is not enough recent progress in our bilateral agenda with Russia to hold a U.S.-Russia Summit in early September. We value the achievements made with Russia in the President's first term, including the New START Treaty, and cooperation on Afghanistan, Iran, and North Korea. However, given our lack of progress on issues such as missile defense and arms control, trade and commercial relations, global security issues, and human rights and civil society in the last twelve months, we have informed the Russian Government that we believe it would be more constructive to postpone the summit until we have more results from our shared agenda. Russia's disappointing decision to grant Edward Snowden temporary asylum was also a factor that we considered in assessing the current state of our bilateral relationship. Our cooperation on these issues remains a priority for the United States, so on Friday, August 9, Secretaries Hagel and Kerry will meet with their Russian counterparts in a 2+2 format in Washington to discuss how we can best make progress moving forward on the full range of issues in our bilateral relationship.