WASHINGTON (Reuters) - U.S. President Barack Obama and Australian Prime Minister Malcolm Turnbull pledged on Tuesday to increase cooperation on counterterrorism and the fight against Islamic State. Obama praised Australia for its support in Afghanistan and thanked the prime minister for his country’s troops’ sacrifices around the world. “We’re going to talk about how we can strengthen our cooperation both in Syria and Iraq, the state of affairs in Afghanistan, but also countering violent extremism globally,” Obama told reporters in the Oval Office at the start of the meeting. “Australia will be a very important partner in that process,” he said. Turnbull said it was critical to improve efforts to fight Islamic State. “We have to constantly lift our game in the way we engage with and tackle these extremists, particularly ISIL - but there are many others - as they operate in the cyber sphere,” he said, referring to Islamic State with an acronym. “Archaic and barbaric though they may be, their use regrettably of the Internet is very sophisticated. And so I’m pleased that we’re going to be working on even closer collaboration there.” The two leaders also discussed their backing of the Trans-Pacific Partnership trade pact. “It is going to be good for our economy. It is going to be good for our workers and our businesses, and it reaffirms that in order for us to thrive in the 21st century ... it’s important for us to be making the rules in this region, and that’s exactly what TPP does,” Obama said. Turnbull congratulated Obama on the implementation of the Iran nuclear deal. 