Asian shares ended mixed on Tuesday as volatility returned to mainland markets and oil plunged following long-awaited deals in Greece and Iran.
Uncertainty still surrounds Greece even after European negotiators and Athens reached a deal for a third bailout on Monday. The news saw global markets rally overnight, with the Dow, S&P 500 and Nasdaq ending 1 percent higher, while the French CAC 40 led gains in Europe by 2 percent. Still, experts warn that the chances of Greece leaving the euro zone remain high.
"Although this deal reduces the risk of Grexit in the interim, it still remains a significant issue in the medium term. Greek politics could collapse under the strain of this new deal and the subsequent elections that may transpire. The viability of the program is also a large risk if the reform process is disjointed or feeble or straight out rejected by new governments," noted Evan Lucas, market strategist at IG, in a morning note.
Read MoreSorry, but Grexit chance is still 'significant'
Oil prices declined over 1 percent during Asian trade after Reuters reported Iran and the six major powers known as the P5+1 group finally agreed on a landmark deal that will give Tehran sanctions relief in exchange for restricting its nuclear program. The agreement is likely to see Iranian crude return to export markets, exacerbating oil's current supply glut.
China markets choppy
Mainland equities swung between gains and losses throughout the session as investors adopt a 'wait-and-see' approach to judge whether sentiment has stabilized following weeks of panic selling. The Shanghai Composite closed down 1 percent after tumbling as much as 3 percent in the afternoon, ending a three-day winning streak. Earlier in the day, the benchmark jumped more than 1 percent.
On the economic calendar, new bank loans rose to $204 billion in June, beating market expectations, while June money supply growth surged 11.8 percent on year, Reuters reported. But the data was unable to boost banks, with ICBC and China Construction Bank leading losses by more than 2 percent each.
Read MoreChina playing dangerous game: Summers
In Hong Kong, casinos rallied on reports that the Macau government may allow smoking rooms in casinos, even as it bans smoking elsewhere. Melco International Development surged 10 percent while Galaxy Entertainment and Sands China popped over 4 percent each.
Nikkei up 1.5%
Japan's benchmark Nikkei index closed at a new eleven-day high, rising for a second session. Sentiment got an extra fillip from a weaker currency as the yen weakened to 123.72 per dollar, a twelve-day low. The Bank of Japan kicks off a two-day review on Tuesday, with a decision due Wednesday, but the majority of analysts aren't expecting any changes to monetary policy.
Sony closed down 1.2 percent after tanked as much as 2.5 percent earlier after the electronics giant declared its first new-share offering in 26 years and said it plans to sell 119 billion yen in convertible bonds on Monday. The capital raising plans are aimed to finance a push towards image sensors and video games as part of Sony's overall restructuring program.
Other industrial exporters were broadly higher, with Nissan Motor and Mazda Motor both ending over 2 percent higher.
ASX 2% higher
Australia's bounced back from the previous session's modest losses, finishing at a twelve-day peak.
Mining heavyweights were the biggest winners, with Rio Tinto and BHP Billiton surging 3 percent each while Fortescue Metals popped 4 percent.
Meanwhile, the Australian dollar strengthened 0.3 percent against the greenback after June business confidence rose to its highest level in nearly two years, according to National Australia Bank's survey.
Kospi dips 0.1%
South Korea's benchmark index retreated from a nine-day high hit in the previous session due to losses among large-cap stocks. Samsung Electronics dived more than 3 percent while Kia Motors eased 0.8 percent.
Elsewhere in Asia
Singapore stocks closed up a modest 0.16 percent following the release of weak second-quarter gross-domestic product estimates. The economy contracted 4.6 percent on-quarter, well off expectations for a 0.8 percent increase.
Indonesia's Jakarta Composite closed up 0.16 percent as the country's central bank kept its main interest rate unchanged at 7.5 percent, as expected by analysts.