美国代表团发言人哈夫说，“我们在各方面都取得了重大进展，但是本星期的工作是高技术性的，对所涉及的所有国家都至关重要。”哈夫还说，“坦率地说， 我们更关注协议的质量而不是时间。 ”
Iran Nuclear Talks to Continue Through Friday
An interim nuclear agreement between Iran and six major powers will be extended through Friday to provide more time for talks on a final agreement, the United States said Tuesday.
"We have made substantial progress in every area, but this work is highly technical and high stakes for all of the countries involved," said U.S. delegation spokeswoman Marie Harf.
"We are frankly more concerned about the quality of the deal than we are about the clock ..." Harf's statement said.
EU foreign policy chief Federica Mogherini said earlier Tuesday, "We are interpreting in a flexible way our deadline, which means that we are taking the time, the days we still need, to finalize the agreement," adding several difficult issues to resolve remain.
Shares Continue Slide in China, Make Gains Elsewhere in Asia
Chinese stocks continued their three-week slide Tuesday, while most of the rest of Asia's markets bounced back ahead of a key meeting on Greece's debt crisis.
The Shanghai Composite Index dropped 3.2 percent by midday, reversing gains from a day earlier, while the Shenzhen Composite Index dropped 5.6 percent.
The losses raise fresh questions about Beijing's ability to contain the stock market plunge, which has already wiped out an estimated $3 trillion in market value.
The government recently announced a series of moves to reassure investors, including pouring billions of dollars into the market and halting initial public offerings.
Elsewhere in Asia, markets mostly recovered Tuesday, with Tokyo, Sydney Hong Kong, Tapei, and Wellington all seeing gains.
Investors are keeping a close watch on Tuesday's emergency meeting of eurozone leaders, where debt-stricken Greece is expected to offer a new proposal aimed at securing an international bailout deal.
Failure to reach a deal soon could mean that Greece defaults on more of its debt, leaves the European Union and discontinues use of the euro currency.